Oh Moose , I do not think it is you. I do think both situations happening in the same week is just pure bad luck.

First issue... the Friends you hung out with last weekend, people can and are a fickle bunch. Maybe she is just super busy? maybe she always just stops talking and signs out to everyone? maybe for whatever reason... she just isn't good friend material. Don't assume its anything you did.

Second issue: Based on all the info, this situation sounds Sketchy to say the least. I would keep calling and at least get paid for the day. I doubt you are the first person that had done work for her and treated the same way. Keep calling, if you have her name goggle it , maybe will show if she has a record at least.

Neither situation has anything to do with you being a bad person , I don't think anyone is out to get you.. Bad luck and timing.