September is a nice time to go. Weather is not to hot and the crowds are down. But if your mother loves Christmas time, you should go around the first of Dec. The parks are absolutely beautiful this time of year and they seem a little more magical. Sit down with her and look at the menus of the restaurants on the computer. Let her choose some that sound good and book priorty seating before you go. Chef Mickey's is wonderful for all ages and great food.(buffet with prime rib) It is a really nice walk to Magic Kingdom from there. They also take a family picture(which you have to purchase)when you come in. A nice keepsake. Anyway, have a great time, don't plan too much and think you have to be on a time schedule. Just enjoy being there together!