I talk to my D's paternal grandparents far more that I ever speak with her actual dad. Her paternal grandmother and I text often. She spends a lot of time with them. I don't know that you'll know exactly what the relationship will look like in the future yet. That being said I wouldn't get in the middle of the fight either. I would stay out of it but I don't think asking if she is ok is getting in the middle of it. If you can just leave it as an actual check in and not offer an opinion or a solution I don't see the harm. If she's the type that will rope you into picking sides, I would definitely leave it no matter what.