<human>: I 25/m have been dating my GF 26/f for almost 2.5 years now and while she and my mom have been getting along fine for the most part, this blow-up was bound to happen. 

A little background: My GF had been in a prior relationship where her BF at the time's parents treated her like shit and would purposely not invite her to certain things. She hated that and she hated the fact that her BF would not stand up for her. 

Fast forward to our relationship: My mom tends to be a tad bit too "traditional" for my GF's liking when it comes to relationships. I live at home and she doesn't let us sleep in the same room (though we do anyway), the holidays are awkward because we are Catholic and my GF is Jewish and so she doesn't feel like part of the family sometimes and worst of all my mother likes to take "family" pictures excluding all of the significant others. Obviously my GF hates this and sees it as a clear sign that she is not part of the family. Worst of all, my sister just got married so now her husband is in all the pictures that my GF is not. Today of all days when all of my family is together, my mom wants a nice big family picture and guess what, my GF is the ONLY one not in the picture. Well, she pretty much packed up her shit and went home right then and there and refuses to come to the house anymore. She claims she isn't mad at me, but I'm pretty sure she is. My mom could tell she was upset and apologized to her saying it wasn't anything personal, but my GF pretty much ignored it and went home.

Part of the problem is that in speaking to my Mom I tend to see her side of the story in that it is just a picture and nothing more. Her rules of the house suck and she can be a bit of a blowhard at times, but she has done a decent job of including my GF in family events for the most part. I'm now home on xmas without my GF and have to figure out how to patch all of this up....An advice?

Can you succinctly summarize the text in 1-3 sentences?
<bot>: My GF of 2.5 years feels left out of the family bc my mom takes "family" photos and excludes her. She up and left at xmas and I'm left picking up the pieces.