I'm struggling on how to help my 7 year old (rising 2nd grader) manage challenges. Whenever she hits a challenge (something that's hard or new to her) she tends to melt down in frustration rather than try to solve the problem or avoids doing it or says she needs to do it "perfectly" and then gets dramatic about it. Some examples:

-melts down over something not coming easily (crying, stomping, etc. - this especially tends to happen if she's losing at a game or can't seem to do something easily like combing tangles out of her hair)
-she avoids doing the task at all if she perceives it too hard or she might get it "wrong" (e.g. riding a two wheeler, writing a note to someone because she might misspell a word)
-overdramatizes doing it "perfectly" (e.g. she exaggerates taekwondo moves that she isn't familiar with because they have to be "perfect," she takes forever to draw out a letter when writing because it has to be just right)

I am a very growth-mindset-oriented parent (heck, I teach grown-ups on the topic) so we've always praised effort, and always talk about continuing to try, step away and look at a problem another way, ask for help, that it's ok to make mistakes, etc., but it doesn't seem to be working. I'm really at a loss where this is coming from because neither DH nor I are perfectionists, we never articulated that she has to excel, etc. and we're big on praise for effort, trying your best, etc, so I'm really not sure what else to try. She's an only child, and she's a pretty quick and advanced learner who's been at the top of her classes so far (and will be in a couple advanced placement groups in the coming year) so maybe she internalized something at school but I am really concerned about her becoming an overachiever and succumbing to stress as she gets older.

Any tips, good books, etc that you might recommend that I can utilize? Many thanks!