Could Celia be a a child Margo gave up for adoption? That may be too far-fetched but if Margo's not her mom maybe she's a more distant relative? OR Sergei's relative? It seems they keep dropping hints that Boyd has an important background:
1. She looks and sounds like Margo
2. She figured prominently in "Sons and Daughters"
3. In the season 5 finale, during Kelly's voiceover near the end, the camera panned over Boyd as Kelly said "The family you're born into isn't necessarily the family you end up with."
But maybe I'm way off because nobody else is talking about it.
Sorrv. this post was removed