Been friends for 4 years. Our DC attend the same school.
DF has always been a bit self obsessed with herself. Something I've tried to look past for the sake of the childrens friendships.
My DC has told me he doesn't want DFs child coming round anymore and doesn't play with them at school as they punched my DC in the face during school (no SEN needs before anyone asks).
DF did punish her child but she's very laid back and regularly tells me her children fight and strangle each other and her child has now been caught setting fires in the local area and hasn't done anything about it, more upset that people have moaned at her for not supervising her child. (Her child is only young) and then moans nobody says congratulations on being a good parent.
DF came round on her own the other day and sat here for 3 hours just talking about herself, she didn't ask how I was, just monologued on and on about herself and her dramas.
I've been through a lot lately with my family and my own health and she didn't ask once about any of it.
She even explained an activity to me she once did like I was stupid and didn't know what it was but wouldn't let me get a word in edgeways to explain I've done the activity myself so didn't need it explaining.
It got to the point where I just sat quietly willing her to leave.
Everytime I see her it's always about her and her drama and I find myself getting drained by it. Even my DH was home and overheard it and said he had a headache from it all.
I'm just wondering really how do I step back from this friendship?
I've already put a lot of distance in and cut back how much I see of her (only when I have the energy for it) but she doesn't seem to get the hint and constantly messages me about her issues. 
I can't ghost her as I see her at the school but I just feel as if this friendship is so one sided. She barely knows anything about me.