What can I do to help my friend?

My friends mother died 5 months ago & she hasn’t been the same since. I try to make plans with her all the time & she never wants to. I don’t get mad at her, I tell her all the time that I understand & that if there is anything I can do please let me know. I remind her I love her & I try to give her the best advice but it doesn’t seem to help. She doesn’t talk to anyone anymore, her mom is all she talks about & she’s severely depressed. Is there anything I can do to help her? Anything at all? She’ll text me sometimes & tell me she’s crying & she just wants to be in her moms arms & at this point I’m not sure what to say anymore cause I feel like I’ve tried to say everything to help but it doesn’t. 🙁 I feel so helpless. I want to help her but I’m not sure how.