M.,
You CAN do it. Talk to your daughters. See what their concerns are.
www.flylady.com
Plan the heck out of things. By the time you are taking the bar (I am thinking 4 years? You'll have to correct for that if it is different) your youngest will be 18.
Plan life, plan activities, plan planning. What will your kids be doing during the next 4 years (make a list). What will you need next 4 years (health ins., health planning - appointments, etc. (not saying MAKE appointments, just have a rough list from doc what you will need).
Simplify your life and possessions. The less you have to clean the better.
Also, plan on wearing a suit to class. One of our local colleges does this with their business majors. Allow for cleaning bills, expenses, clothes, wear and tear, etc. Even if you are changing into a suit for class like you change into gym clothes, it's a planning thing. Wearing the suit also gets you into the mindset, too.
Be careful of rote memorization and core dumps. The first is hard to use years later when you need it. The latter doesn't help you at all. Develop a system that works for you for remembering vast amounts of information. A tickler file would be a good idea (3x5 cards with tickle info about subject and cases). (tickle your memory into remembering useful info).
Look at the hardest times for your kids - you might need to take time off from classes altogether - for your sanity and theirs. Plan around that if you can.
Do your homework with your kids.
Have your kids help you with meal prep, etc.
Have your home concerns checked out ahead (if not in an apt, that is). Remember you can't let maintenance and upkeep go during this time.
There's so much more you can do to help you and your family.
But most of all: What would you do and where would you go with a law degree? Will it take you from family? Where do your girls want to go to school? How will you get them there?
Finally - go gangbusters on scholarship and grant applications. it can't hurt. It'll show your daughters that there is a way to go to college if they really want to go.
Good luck,
M.