Need help with Caste discrimination and status discrimination! Don't know where to post!

So Me and my girlfriend are from different castes! So my side of family are okay with my relationship. My girlfriend revealed this relationship with her family. Her family can't accept me as I am from a lower caste and lower financial status compared to them. Now the problem is they are against this marriage Her mom called me the other day and she spoke like your status and your caste doesn't work for our family. This hurted me deeply and I said to my family asking them to speak with them to convince them. They are hurted as well, as my girlfriend's family discriminated about our status and caste. My gf is stubborn with this relationship. She has been house arrested, she doesn't have phone. She is fighting with her family. We have planned to wait and fight till they accept. Now the problem is my mother is hurted as they spoke like this. She is unhappy with my girlfriend's family. Now I am confused I want to marry my girlfriend, but I am also looking into my mother being unhappy how they spoke. Need some advices in this situation. Whom side should I lean, towards my unhappy mother or my girlfriend fighting for me over there?