Ms. DeVos’s support for her gay friends and for lesbian, gay, bisexual and transgender rights are a largely unknown but deep-seated aspect of her history, dating as far back as the late 1990s. At that time, two colleagues recalled, she made accommodations for a transgender woman to use the women’s restroom at a Michigan Republican Party call center. She also used her political connections to help persuade other Michigan Republicans to sign a brief urging the Supreme Court to legalize same-sex marriage in 2015, though she did not sign it herself.

This aspect of Ms. DeVos’s personal story is not only at odds with the public image of her and her family as prominent financiers of conservative causes, but it also stands out in a nascent administration with a number of members who have a history of opposing gay rights. A Senate confirmation vote on her nomination is scheduled for this week.

The incomplete picture of Ms. DeVos, 59, exists in part because she has never publicly sought to correct it. Doing so, friends and associates said in interviews, would have put her in the awkward position of clashing with the elder members of her and her husband’s families, something she was loath to do.

But over the past month, associates have come forward to share stories that they say they hope offer a fuller and more nuanced portrait of her character and beliefs.

“She would say it’s a part of her faith,” said Mr. McNeilly, who has worked for Ms. DeVos in various capacities for two decades. “Her faith teaches her to be tolerant. And like most of America, she’s evolved.”