OK, so the feedback is valid, but your colleague is overwhelmed. I have some experience navigating such situations, but let's start with the metaphor of feedback.
"Feedback" is a term originally coming from Electrical Engineering and Classical Control Theory, what happens if you amplify (increase the gain of) the feedback too much?
That is right: the system overshoots, or even worse starts oscillating wildly and becomes unstable, never reaching the set point. I'm convinced that this corporate culture of requesting and giving too much feedback can have similar effects on people and teams.
This metaphor is getting really stretched, but point is - your colleague is either receiving way too much feedback when she needs support instead (team/managers fault), or she is amplifying that feedback way too much and feels overwhelmed and starts doubting herself.
Giving too much feedback is a thing, because it can be both valid and a waste of time - when I was a team-lead I was encouraged a lot by managers to give quite a lot of feedback; it HAD to be given, the sheets filled in. A lot of noise seeped in, things that weren't that important that either overwhelmed team members or angered them when they felt it was unfair. And it can be both valid and unfair! And unfairness is the easiest way to demotivate someone.
Eventually I learned that some things are better left to individual to learn on their own speed and through experience. I also noticed experienced managers paid lip service to the feedback culture, but rarely gave feedback, unless they felt it is very, very valuable. But then the best managers and team-mates I can think of also know how to be very supportive in both subtle and open ways.
A lot of people argue that giving feedback is a subtle art and it can be supportive as well, but that sounds like "No true Scotsman" to me.
So what would the advise be? Just food for thought - is the feedback too much and/or is your colleague influenced a bit too much by it?