Erin is a vivacious and often outspoken voice on social media, an acerbic sometime writer in the golf press and the author of a blog called Tour Wife Travels, for several years a travelogue of life on the pro golf circuit.
Her Twitter bio reads: "Professional golf watcher. Amateur show jumper. Married to @jimmywalkerPGA. I'm opinionated. He's not."
A lively and lengthy phone chat with CNN from Utah confirms as much.
Up until last year, Erin spent roughly 30 weeks a year on the road with Jimmy, having forgone her own dream of going to law school.
But instead of settling down to a life of hotel-coseted luxury, the journalism, advertising and marketing major took on the role of CEO in Team Walker.
Among her "many hats" are financial controller, contract reviewer, travel planner, event organizer, sometime swing guru, chief motivator, psychologist, wife and mom.
"I'm the one who runs his ship. I'm doing everything else, just making it as easy on Jimmy as possible so all he has to do is go play golf."
The couple, based in Boerne, Texas, traveled around the circuit full time in an RV when the kids, Mclain (now seven) and little brother Beckett (four), were younger. Kindergarten has curtailed the road trips, but Jimmy still uses the RV for select weeks. He has a driver because coach Butch Harmon is "very anti" him taking the wheel himself (too stressful).
"It's a house on wheels," says Erin. "We have our own bed, our own pillows, a washer-dryer, a dishwasher, an American-size residential refrigerator, four TVs, the kids have bunk beds, we've got four pairs of rain boots, stuff you can't pack week to week.
"I think you have to be a little bit adventurous because there's always something broken."
At the Masters they park across the street from the Augusta National.
"Augusta is amazing," says Erin. "Jimmy walks in every day and it's great for the boys to have a huge yard to be able to kick a soccer ball in or play baseball. For us it makes sense."
If life wasn't already enough of a juggle, Erin fits in her passion for showjumping, competing in about 15 events a year around the US.
Keeping her horses with her trainer in Virginia adds another level of complexity to the operation.
"It's hard, I don't get a lot of practice," she says. "I just kind of show up at horse shows and hope it goes it well. Luckily I'm athletic enough but it's difficult. I want to be better and jump bigger jumps but I have to adjust my expectations.
"But I'm lucky I have a husband who is supportive of it because for me I have to have a hobby and kind of do my own thing a little bit."
Erin's fire comes from her parents, both competitive skiers in Utah in the 1970s. Her dad Mark Stiegemeier was the world freestyle skiing champion in 1975, and she and her younger brother Sean grew up ski racing, crossing paths occasionally with a young Lindsey Vonn.
In 2015, Erin walked around Augusta with Vonn, then girlfriend of Tiger Woods, and swapped tales of mutual friends.
The obvious upsides to a successful pro golfer husband are the riches -- Walker's career earnings are just north of $23 million -- and the perks that come with the fame.
Erin ticked off a "bucket list" VIP trip to the Kentucky Derby this year, while Mclain was able to meet his Nascar driver heroes when Jimmy attended the US PGA media day as defending champion. There's also the Masters tradition of partners and children donning the white suits to caddie in the Wednesday par-three competition.
Then there are the trips abroad and the camaraderie of the team events, such as a "hysterical" wives' day out eating squid and other unidentified food during the 2015 Presidents Cup in Incheon, South Korea.
Or the electricity around the stadium-like first tee on the opening morning of the 2014 Ryder Cup at Gleneagles. "It was an incredible feeling," she says. "Even right now I get goose bumps. You never want to miss another one."
But the downsides to the lifestyle come not from travel hassles or time apart, but from an unexpected quarter. Social media, a force for good used in the right way, has become the biggest trial to life on tour. It's caused several "bumps in the road," she says.
"I knew when I married Jimmy he would be traveling, I knew when we had kids he would be traveling and I would be a short-time single parent, so I can't exactly say that's a negative," she says.
"But the bigger name you become, the more people want to tear you down, which I just don't really understand. People have their assumptions and there's no recourse for what people say.
"Even somebody as popular as Rickie [Fowler] has the haters. I'm like, 'What do you mean Rickie? He's the nicest guy out there.'"
Erin says they have both had to develop a thicker skin, and admits she has had to "curb" the instinct to fire off replies to every detractor. "I'm pretty politically correct," she says.
"I'm not going to say things that are going to irritate him and his sponsors but I am going to say things that apply to our everyday life."
"She does a good job. She sticks up for me," Jimmy, 38, told CNN at the British Open at Royal Birkdale, where he was sharing a "frat" house with eventual champion Jordan Spieth, Rickie Fowler, Justin Thomas and Zach Johnson.
Stresses & stargazing
For some Tour wives, life in someone else's paradise is not always a bed of roses.
Erin knows of other spouses who have given up ambitions to be attorneys, dentists, even pro golfers to support their partner.
She says she can "1000%" empathize with Brittany Horschel, wife of PGA Tour player Billy Horschel, who recently admitted she was an alcoholic, and spent two months at a Florida treatment center. She has been sober for more than a year now, but says the drinking was aggravated by loneliness of caring for a baby daughter out on the road.
"Everybody deals with the stresses in a different way," says Erin, who met Jimmy when she was a volunteer at a second-tier event in Salt Lake City in 2004.
"I absolutely can see how -- especially going from where she was, a very good college golfer -- having to suddenly be like, 'OK, I'm giving up my dream to go support your dream.' That's a huge transition.
"That's why the horses have been so important for me. It gives me a positive outlet.
"I really applaud Billy and Brittany for putting their story out there."
Erin believes it's vital for the players to have other interests alongside golf, too.
Jimmy's is astrophotography, and he's won awards for it. Three times NASA has made his pictures its astronomy photo of the day
"I love it for him that he has a hobby besides cars and wine because every pro golfer likes cars and wine," she says.
"This is something that's unique and gives him a way to get away from golf and be creative and find his zen place.
"It gives him perspective on everything. There's a lot bigger stuff going on out there than golf and making birdies and bogeys."
Coping with Lyme disease
Jimmy's nights spent at the telescope -- and on the golf course and range -- have been curtailed since November as he has battled a debilitating illness which has sapped his strength.
In April he was finally diagnosed with Lyme disease, a bacterial infection spread by infected ticks.
Walker told the PGA Tour the disease "feels like you've got the flu. No strength. Just got nothing. And it comes and goes in waves. You never know when it's going to pop up."
He is on a cocktail of drugs and vitamins, and told CNN at Royal Birkdale he was operating at "75-90%."
"I just don't feel myself, I don't feel strong," he said.
"It's been hard," added Erin, who has become a vociferous campaigner warning people to beware of ticks.
"Jimmy is not vocal and he's not a complainer so he's not going to be the one that says, 'this has kicked my butt this year' but it has.
"It's been affecting his mood because he didn't feel well, and that's straining on a relationship and straining with the kids. I'm happy we're heading in the right direction and he's starting to feel better."
Erin's had to add pharmacist and nurse to her long list of roles.
Just don't try telling her that all she does is shop and spa