A mother shouldn't have hair. She should have a roll of paper towels extending from her skull so she can wipe up any spill at any time.
A mother shouldn't have only two hands. She should have a third hand with a warm, soapy sponge attachment so she can clean up stickiness.
A mother shouldn't have regular thighs. She should have deep pockets in her thighs so she can store all the little things that children need. One of these pockets needs to be self-cooling so she can keep a child's lunch cold.
A mother shouldn't have only two eyes. She should have eyes in each elbow, on her shoulder blades, and at the back of her ankles. All these eyes should open and being recording data automatically if something happens that might begin a "he said she said" or if your child tends to disobey as you are turning the corner out of the room. This would also help in taking snapshots of all the precious moments that should never be forgotten.
A mother shouldn't have knees that bend only one way. Instead, she should have double bending knees so that the child that bounces on them for horsey could get a really good ride. It wouldn't hurt if the knees also had springs or shocks for added protection.
A mother shouldn't have only one mouth. She should have one that goes to an internal trash bag that never needs to be taken out. Instead all the trash she picks up every day from the floor should be recycled into extra energy.
A mother shouldn't have ten fingers that merely move. She should have one that spouts the drink of her choice at a moment's notice. Coffee, water, and other occasionally enjoyable beverages should all be available on command.