Elizabeth,
Sorry to hear about your "learning" experience so far, and good for
you for having the determination to keep going.
I would suggest taking the small boat instruction available near you.
Small boats handle like big ones, but respond quicker. And since they
are 1 person boats, you (and your daughters) learn how to be the
captain for real. Once you can sail a small boat the bigger boat will
be easy. Docking isn't as hard as it looks, if you take it slow and
easy.
Learn the basic rules of the road. Don't worry about the complicated
ones.
If you can take a week long course, do it. Me and my girlfriend did a
week a Jworld when I started taking her sailing, it was a very
thorough course (
http://www.jworldschool.com/).
Sail the small boats, then keep at it.
Todd