Okay, I've seen most of season 6, but am I just having a total lapse of memory on who this girl is? How is she related to the other characters on the show, what does she do?
This is a picture of Anna from The Perfect Dress
in season 6.
She is an old girlfriend of Luke's, and the mother of the daughter (April) he finds out he has in season 6.
You may also recognize the same actress as Sasha (Jess's father's girlfriend) from Here Comes the Son
in season 3.