Awww ScottishBurd. Your poor friend. Sounds like, if she can fly, then you should try and cheer her up and help her find a decent instructor, who can help boost her confidence a bit.
There's a whole stack of people out there including me, whirly, etc., who had a miserable time around the start, but who managed to get it all back on track through sheer force of will and bloody-mindedness, eventually.
I quit the engine stuff to fly gliders and to try and fall back in love with flying again. I was helped in this by a wonderful bunch of instructors, Dave Larsons, Ingo, Steve Nichols and Pat Brown who collectively had me solo in a couple of hours flight time, but more importantly, taught me the behaviours and confidence required of a student, that had **never** been taught to me before.
Confidence and good decision making are important to you when you are PIC, but are also crucial for any kind of flight test be it a skills test, a BFR, a checkout, or even dual with a new instructor.
I think there is a set of people in the world who would rather sit back and listen, and who are attentive to every word, nuance, gesture and intonation of the person teaching them to fly. This can be a killer, if the person teaching regards this as a weakness.
My flying improved when to a certain extent I stopped listening quite so much, and started regarding the aircraft and the decisions as mine, until definitely informed otherwise. It was a great step forward when an instructor informed me that, while he might have flown slightly differently, I had done a perfectly good job and he was happy to sign me off.
As far as being embarrassed at being a student goes, maybe she just needs to think of the end result, the freedom, the achievement, and it **will** be worth it. Brazen it out !! 50 hours or 100 hours, she'll still be a pilot, and that betters 90 % of people, like it or not.
Keep her at it. Good Luck !!!!