CJR....I'm amazed that your daughter would even THINK to ask you to pay for her college at yours and her ages! You and your husband sound like such sweet and caring people, but it also sounds like daughter is manipulating you, and especially your husband.
Like Perna and others here, I'm 57. I went back to school in my late 30's while I had a small child at home. No one paid for this but me! I also worked my way thru undergrad school, and now footing my own bill toward the MA.
With your retirement in sight and nearing, you must take care to be financially secure yourselves! Don't let your hubby be swayed by daughter. It is rather scary to approach retirement even with what appears to be financial security, much less so, when giving out a fortune for someone's college education. Your daughter must make her own way, and be happy you are taking care of your own future!
Love
Patty