In your first post you list 3 adults and 1 child, and then later you add that Mom decided to join you. If that is the case, you'll have 4 adults, and 1 child traveling in your party. Is it you, a spouse, an 11 yo and 3yo plus Mom?
You will ALL need to be listed on the All Stars reservation, if you plan to get free dining for everyone, and the credits can not be shared by those not on the
DDP reservation, or you'll need to pay out of pocket for someone's dining.
From the
Disney Dining Plan Brochure: