I don’t think you have any experience with eating disorders or women in general. Someone who used to be skinny gaining a bit of weight and feeling fat is not “behavioral patterns connected to anorexia/ bulimia”. And even if it was, how does “this is clearly freaking you out, let’s ignore it and do this instead” supposed to help?
I’ll assume you have the best of intentions in mind, if that’s the case you really shouldn’t be giving advice here because everything you’ve said so far is harmful.