advice on miscarriages

my best friend keep having miscarriages & nobody knows why. It's really putting her in deep a depression. I think she feel even worst because I just had my own baby. Is there anything I can do as a friend? My baby is in NICU & I told her she still has a God daughter to love to try to make her feel better but idk. She's lives 4 hours away from me now. Do you think it'll be a good idea to drive down to spend time with her to try to make her feel better?