Girl - I've met you - she's jealous.
Maybe she is one of those women that just feels hateful the older she gets ?
She does sound miserable and I would just steer WAY CLEAR of her. Ignore her as well as you can - there are people in the world that never have anything nice to say about anyone .....people like that want the REACTION they get...it's like any attention is good attention to them....maybe talking like that makes her think she's getting attention.
ps. If you've done nothing to her - then let HER be the one to apologise - you tried