What can I do in this situation with my girlfriend? I haven't seen her in 3 months now?

So here's the thing. My gf's parents are divorced. Her mom lives in Nyc and we're from Wilmington NC. My gf in January had a fight with her dad. Afterwards she went to her mom's. I thought it was gonna get fixed quickly between her and her dad. Especially since they fought over something stupid. However they haven't. They are both so stubborn and (stupid... at least for something like this) that they still haven't  figured this out. Now she's been in Nyc for 3 months with her mom. And because she still hasn't made peace with her dad she's not coming back anytime soon. Until she doesn't make peace with her dad she won't come back basically. I thought about her staying at my house but I really can't do it because I have a newborn sister and my parents don't want anyone in the house. I thought also about goint to Nyc but I can't do it now and it wouldn't be the same thing. I tried reasoning with both her and her dad to help them make peace and it didn't work. What would you do? I love her and miss her but honestly I can' t take this anymore