I'm honestly not sure if you're being snarky here or not, but this seems a non sequitur. That's not Erin's mother. I mean, I'm sure there are some pretty oddball families out there, but it's pretty unusual for a mother to refer to her daughter as "mom."
It's laguna85 who initially said that:
forgot to add happy that mother stop her daughter from kill herself.
I queried that since I wasn't sure if I was missing something or if it was just a typing error. Eventually laguna85 said that the woman could be Erin's mother or her daughter.
I'd already pointed out that she calls Erin Mom but that hadn't swung it. So I was suggesting that since 868 indicates that Erin was present when her mother was killed, and she was at least in her teens, she must know what her mother looked like. So if this woman is her mother, why doesn't Erin recognise her?