also do this:
record the vocals twice. first time, set the controls to capture the
quiet stuff well, and let the blast stuff overload.

then record again at a low gain setting, the quiet parts will be down
too far, but the blast spots won't clip.

blend that in with the other advice, and you should get what you need
on disk.

if she's a prima-donna and can't be taught, but has no problem cutting
her vocals multiple times, just make her slave it out and then comp it
in the daw.