B.,
You have gotten some great advice! Here's my two cents:
1. Check out www.flylady.net, if you aren't a member already. It's a great, free, website where you can set up routines, a control journal, etc. Since you have all summer to get routines set up and your home ready for auto-pilot for your husband, then hopefully your home and family won't be a wreck when you get back. This way your children will have a sense of security from their routines and how the house is run and your husband can look at your control journal and know what things need to be done at what times of the day and how.
2. Go on a couple of day, over-night, or weekend trips with some of your girl friends. Get your kids, husband, and you used to the idea of mom not always being around. Then when you are gone for 10 days everyone will have an idea of how things will work and know everything will be fine.
3. Make sure you take lots of pictures with you and your mom while on your trip. Send postcards of places you visited to your kids. Every child loves to get personalized mail! Tell each one a little bit about your trip (something different for both your son and daughter), and don't forget something special for your Dear Husband. He will appreciate compliments and thank yous for giving you a bit of time off and taking care of everything.
4. Don't feel guilty!!!!! There are only two jobs in the world where the employees don't get time off.....parents, and children who care for their aging parents.
We all need regular breaks, vacations, and time to relax without constant demands on our minds and bodies. GO HAVE FUN! Create new memories with your mom and enjoy your vacation. You have earned it!
Good luck in the fall.