No dream is ridiculous. It has been done and it can be done. I realize you have extra challenges as a mother, but don't sell yourself short. You can either go for  the medical school thing, or try to find another career you'd be happy in with less work time and training. For example, you could be a physician assistant, nurse, nurse practitioner, pharmacist, etc. All take less training than a doctor, and once you're done you can work a normal work week. good luck and don't give up until you find a way to be the mom you want and have the career you want.