Outsider Looking In

I know this girl.  Her name is Erika (name has been changed to protect the not so innocent), and she talks to me about her relationship all the time (and she doesn't mind that I'm writing about her).  She's in love.  Not the love that sounds nice where all appears to be well. She's in that deep, head over hills, cliche, put up with the stuff that pisses her off type of love.  And he loves her back, but he loves in a different way.  It's not that he loves her any less, his love is just manifested in a different way.  He's affectionate.  Sometimes.  He tells her how he feels.  Sometimes.  He treats her like a princess.  Most of the time.  For the most part she's happy.  She wouldn't trade places with anyone, but like most women there are some things she would tweak, but at least she realizes how good she has it.  She appreciates him and everything he is to her.  But one thing tends to nag and nag and Erika said it's close to eating her alive.  She doesn't want to let it bother her, but it does.

She's dated him for a while and she feels like an outsider looking in on his life when it comes to family.
It's not that she even needs to be included always, but its like she's always kept separate, in her own compartment, and only really brought out when there's no one else around.  And she doesn't think its done on purpose or done maliciously its just done.  She doesn't seem to want much, just to be included.  Maybe it's because she wants a future and a family with this young man or maybe it's because she loves him so much, but no matter what it is she knows that she hates feeling like an outsider.  For once she wants to truly feel apart of him, his family, and the most important aspect of his life.  I want to help her, but I just don't know how...