^^^Agreed...she is very typical for a younger player. Just remember this is a marathon not a sprint...start with one or two things and take it a step at a time, she can be taught the whole swing at once but she should only focus on one thing at a time. the last thing you want her to do is be at the plate thinking through the 8 point or 10 points of the swing...that is the muscle memory part your DH is talking about. Also even though she is young don't be afraid to show her pictures of herself vs model and then put her in those positions so she can FEEL the difference.
I absolutely agree its a marathon, and that you can't be overthinking while swinging against game pitching.
But I also think that you CAN and MUST work on "8 or 10" things if those things are broken. Work on them with drills/practice. Many small fixes will have significant downstream impacts, and NOT fixing them will hold you back from making gains. Many of the things I'm thinking of can be set or established before the ball is in the air, even in practice. Skip 6 or 8 things to work on 1 or 2 and you may end up frustrated because you aren't getting the results you want because everything is so dependent.
For instance, you can't just
stop the hands drop/barrel dump/lay bat flat then dragging bat all the way around elbow
by working on THAT. You need to set a better platform (grip, stance, posture), install an alternate "engine" (DBSF is really an engine, it powers swings without stretch and fire engines), and change swing thoughts to make real progress. In short...
She does need better coil, separation etc and lots of other things