My 13-year-old daughter is severely depressed and has body dysmorpia disorder.  She's in a very low and difficult place right now.  She's literally starting antidepressant meds and neurofeedback treatments in the next few days to add to her counseling sessions...so there's hope on the horizon here.  

But today she said she feels no connection with her best friend of many years.  These two have been attached at the hip forever, having sleepovers almost every weekend, and remained connected throughout the pandemic.  They are both homeschooled and used to facetime every night, thoroughly enjoying each other's company and having a blast.  To hear my daughter say she feels no connection and not having fun with her any longer scares and confuses me.  Without this friend, she literally has no other friends right now.  She's been homeschooled (as has the friend) and she lost contact with the other friends when her small private school shut down during covid.  In truth, she had little in common with them as much as she tried to connect...so it's not as if there's anyone in that group to reach out to.  My daughter tends to be kind of a one-close-friend kind of person and this is the one girl who "got her" and vice versa.  I'm so scared she'll push this girl away and then when she comes out of this depression, it'll be too late.  

I know some of my fears are related to my own experience at her age when I lost a best friend due to very different circumstances. 

I guess my main question here is that I'm wondering if it's normal or common for someone to feel differently about a friendship while depressed?  Should I be doing anything to help this or just stay out of it?  I know I cannot force my daughter to feel something that isn't there but I wonder if I should speak to the friend or her parents?  Her parents know my daughter is depressed but are not aware of the concerns I'm expressing here.  I feel like I want to save the friendship if I can but not sure if my daughter's depression is the cause.  I'm a bit emotional right now so I could definitely use some outside perspectives here.