I think a lot of this depends on how you view the word "excuse."
To me excuses are just what you tell yourself or others to get away with bad behavior..
Things like c-sections, postpartum depression, etc. are reasons not really excuses. Mostly because the word "reason" implies there can and often is a causation.
I agree that she is a bit of a fat shamer, I was disappointed when she said that large women shouldn't be proud of their bodies. I think she should have stuck her previous line of argument about health and taking time for yourself as mother and woman.