Ms. Wheatley said she tried to set Ms. Donaldson up with dates, but to no avail. As spring turned to summer, the two attended cast parties and took walks on the beach. They saw each other daily at the theater. When Ms. Donaldson’s parents moved, she and Ms. Wheatley went to the house in Claremont to clean it out. They sifted through old boxes and commiserated over how to care for their ailing parents. Then, Ms. Wheatley realized her friendly stirrings were turning romantic.
“The person I am supposed to set you up with is me,” she said she told Ms. Donaldson. “We went out for tacos and I talked about my kids.” She added, “Being in this relationship is not about me coming out of the closet.”
That is how Ms. Wheatley explained it to her brother’s family in January 2016 after she and Ms. Donaldson began dating, and the show left San Diego for Seattle. The two went to Cincinnati for the funeral of her mother, Mary Jo Wheatley, a former hospital administrator at the University of Cincinnati Medical Center. (Her father, Charles Wheatley, is retired.) Buzz Wheatley, her brother, recalled having coffee with the couple at his house with his family after the funeral.
“Sharon was talking about how she didn’t identify as gay,” he said. “And my daughter, Elizabeth said, ‘You are Martha-sexual.’”
The explanation sufficed. But if Ms. Wheatley was increasingly sure about her feelings, Ms. Donaldson was less so. “Sharon had to hunt me down,” she said. “I said, ‘You are great, but I don’t want to be in a relationship.’” Ms. Donaldson had not spent a lot of time with children. “She was afraid of kids,” Ms. Wheatley said. “I said: ‘I don’t need you to be good with kids. I just need you to be good with my kids.’ I was so certain of it.”
The couple moved in together in August and, last fall, were in Toronto for the debut of “Come From Away,” in which Ms. Wheatley continued to perform. Her daughters were more than happy with their mother’s girlfriend, who became a grounding presence. “Mom is much stronger and happier with Martha,” Charlotte said. Beatrix, though, wanted a more permanent arrangement.
So, during Thanksgiving, in a Victorian house the couple rented, Ms. Wheatley said Beatrix bent down on one knee and “popped open a ring box and said, ‘Will you be my stepmother?’ Charlotte said: ‘Me too! Me too!’”
Ms. Donaldson said yes. But even so, she was preoccupied with doubts. “I said the reason you don’t really believe in marriage is because for so many years you weren’t allowed to get married,” Ms. Wheatley said. “It didn’t mean anything. Well, she said, ‘Be careful what you wish for because when I turn the corner, I’m really turning the corner and I may be more than you want.’ And I was, like, bring it on.”
A month later, on Dec. 25, Ms. Donaldson and Ms. Wheatley unwrapped their Christmas gifts from Charlotte: a set of “Mrs. and Mrs.” hand towels, a present that didn’t go over well.
“I was feeling: ‘Hey. Hey. Everybody cool it,’” Ms. Donaldson said. “But it was important to Sharon that she be married. And I was, like, we can be together forever. Then we got into an argument about whether we were going to get married. She said, ‘I’m going to take a bath.’ I said, ‘I’m going to take a walk.’ And as I was walking I thought: ‘What am I waiting for? What is the difference?’ For her, there was this fear that I was going to leave. And, for me, there was comfort that I could leave at any moment.”
Ms. Donaldson roamed the streets of Toronto for more than an hour and returned home. “I was yelling at myself: ‘Don’t screw this up. It’s the best thing that ever happened to you,’” she recalled. “It is by far the most mature relationship I have ever been in. But I had to talk it out. There was nothing else I was waiting for.” The next morning, Ms. Donaldson got down on one knee and proposed to Ms. Wheatley. Charlotte and Beatrix squealed with delight.
During the wedding ceremony — which was officiated by the actor B. D. Wong, who was ordained for the occasion by American Marriage Ministries — Beatrix wore a white dress and a crown of posies, and carried a rainbow-colored lollipop with “Sharon” taped to one side, “Martha” on the other. Charlotte also opted for white, and a flower crown, while Ms. Wheatley wore a blue floral dress from Lord & Taylor.
Ms. Donaldson beamed as she looked at Charlotte and Beatrix. As part of the ceremony, she agreed to “marry” them too. “Thank you for welcoming me into your life and for allowing me and encouraging me to marry your mom,” she said.
Guests wiped away tears. Some later suggested that Ms. Donaldson’s “lone wolf” persona was solely a defense.
“That wasn’t really true,” said Ellen Bonjorno, a friend from Port Townsend, Wash., who has known Ms. Donaldson for more than two decades. “I think she was afraid to hope that she would ever have a relationship like this.”