Anything is possible, but considering Stephanie is going to Amber to get help with self confidence for dating (among other things) and Claire's bingo card, my guess is that she's alone at the moment. I am also wondering if she has a connection to Nika from before - that moment when she wants to do shared therapy with Nika is very different from her meeting with Vic after class, the way she stress smokes after seeing him, again not like her response to Vic. You'd think hitting a person with a car would be the trauma that needs to be resolved, not therapy with a bystander. She might as well ask the police for shared therapy. When she mentions that NIka's part of her problem, I can only see that she either knew NIka's parents, or she knew Summer even if Nika doesn't know her.
It could easily be Summer was her niece. That's just a wild stab, but the way she sdjusts her clothing when rescuing NIka, the therapy, the phonecall where AMber says she's got someone in mind for her, and the dress looks wonderful - all that suggests if she's married, she's separated.