I hope you're using the term "friend" loosely, cos honey she ain't no friend! It doesn't sound like she's all that invested in staying with your T since she was wanting to jump ship to another T anyway so maybe it would be a good suggestion.

The giving away your appointment is a strange one but i wonder if your T started asking clients to cancel, you were one of the first she canceled and then when speaking to your friend she refused to cancel, kicked up a fuss so maybe T gave her the free slot? Or your friend could just be lying to rile you i dunno.