Susan Kaplan said she’s never given a marketing seminar. She doesn’t hand out business cards unless she’s asked for them. She doesn’t even really have to sell what she does in group settings. She’s never had to market herself because other people are usually doing it for her. She’s got so many referrals, she’s now reached that particular form of advisor Valhalla in which she has to turn them away—referring six to eight clients a week to other firms, she says.

And yet she’s engendered such trust that sometimes her clients tell her they want divorces from their spouses before they tell the spouses themselves. She recalls that one client’s child even came out of the closet to her before telling the rest of the family. Recently, while eating at a Left Bank restaurant in Paris, she recalls running outside repeatedly to tell a client how not to muck up a real estate deal.

“She was asked to bid over ask and drop all contingencies,” says Kaplan. “I’ve been involved in eight real estate investments, and every single time somebody has said it’s priced to sell and someone said to offer over [the asking price] it was wrong, wrong, wrong.”

Hard to imagine now, but Kaplan used to be an ICU nurse monitoring the vitals of unconscious patients. But since the late ’80s she’s been a financial advisor, and her 20-plus-year-old firm, Kaplan Advisors, has now gathered $1.5 billion in assets and landed her on Barron’s list of the top financial advisors in the country in both 2012 and 2013. Her expertise earned her a radio show she co-hosted in Boston for more than a decade (The Money Show on WTKK) and won her a role in the top advisor class in a very competitive Beantown.

She says her growth has been steady. She started with $50 million in assets in 1993 and now has $1.5 billion—all without hiccups or layoffs and without hitting the asset ceiling so many others do.

How did she do it? A mix of personality traits, she says. She’s conservative and doesn’t like to blow money on overhead until she has to. She’s paranoid and doesn’t like other managers handling her clients’ money (she invokes the ghost of Bernie Madoff) or back office broker-dealers sending them mail behind her back.

She’s also got a “bring the family” attitude toward her clients, and gives advice to the kids and spouses (and sometimes even girlfriends) for free. She doesn’t sell products like annuities even though she could. For her virtue, spending time on analyses for people who are not yet clients, she has on occasion been told she’s doing it wrong—giving advice away for free. For staff, she likes to pick the apple right off the tree—getting analysts right out of school and teaching them herself rather than trying to retrain someone who’s been in the polluted waters of the sales business.

She says she never even intended to start her own business. She began in the nurturing bosom of an insurance company. Her financial planning business took off within and then organically split off from it.

It sounds like impossible kismet. So many advisors have trouble breaking through the asset ceiling—say, $200 million—she knows, and yet Kaplan has persevered with shrewdness and by letting other people be her best voice and in such manner joined the $1 billon club without suffering the degradations of two bear markets.