Mac,

Probably she was caught by several lines together under the hook. That and the fact that these lines are normally under great tension explains everything. A V-hook will only help a little bit more in this situation.

The main problem in this kind of situations is panique!

If she was for instance caught sitting upon the tramp during shifting from site to site, she would have had normally no problem with shifting the ropes free from her hook.
But seeking under water the ropes which you cannot see and then shifting them from the hook in the right direction is another matter!!!
Especially when when you think you are drowning.

Only a real marine training would help her with this.

I hope sincerly that the fear will not pin down in her mind. It is important that she goes sailing again as soon as possible!

All the best.

ronald