FWIW, an outsider's opinion.
If, as reported, Flt Lt Stewart felt unable to continue then surely she should be respected for having the courage to say so instead of carrying on regardless and potentially putting herself and others at risk?
It's not the first time someone has asked to leave the team. There is at least one pilot (with previous display experience) who was posted to the Red Arrows (as Leader) and asked to leave during pre-season training because he realised that it wasn't for him. He went on to achieve extremely high rank.
FL