If she is not mentally ready to do it, that is fine, but don't bring you down with her (what seems to be purposefully) hurtful, irritating posts. Explain that you treasure your friendship; however, you need someone to support you, even if she isn't willing to try to better her life in the same way.
Blocking her is a short term solution IMO cause she will want to know why you don't respond to things.
If she posts an a comment about how you are losing too much weight, counter it with fact - as in..."I'm working towrad a healthy weight where I feel great about myself!"
You can't force her, and it sounds like she looks up to what you are doing, but isn't ready to do it herself, so she retaliates against your efforts in hopes you will follow her track.
I am an open & honest person, so I feel that is the best policy. Either she understands or she doesn't. And, perhaps if she doesn't understand, you can delete her anyhow, and your problem is solved!!



