She has walked out of your life because she is young and has a full life and may have problem's in her life that are distracting her
If you want her in your life the effort is going to need to come from YOU
You make the effort go see her call her if she does not pick up call again til she does
You say Mum has mental health issues not a good thing for your GD to have to deal with or live with day in day out you don't know what is going on in the household --just looking at the bigger picture
I think your a lovely caring GM but maybe u r focusing on urself a little too much NOT saying that in a bad way I have done the same
Make the effort sweet she probably needs your support
Have any of you got all electric cars? Pros and cons please.