check to see if any schools have an evening program. I go at night starting at 5pm. This way you can be home during the day with the younger children. It is not easy to manage but if you really want...
I started at age 49, I will be graduating in less than 2 weeks at the age of 51. My youngest graduates from high school this year so I know where you are at. You are never too old. It is not easy...