Hey Janet!
Thanks for stopping by the Disney Parks Moms Panel with your question! I'm sorry to hear that you have been unable to add additional Guests to your Advanced Dining Reservation at Chef Mickey's. Rest assured, there are several other amazing Table-Service restaurants that offer Character Dining. You may consider trying Best Friends Breakfast, which is located at 'Ohana in Disney's Polynesian Village Resort and traditionally features Lilo, Stitch, Mickey and Pluto. Please know that characters are subject to change. This is a family favorite for Character Dining because the amazing breakfast offerings are served family-style and are all-you-care-to-enjoy. The characters will stop by for photos and autographs while you enjoy a delicious meal. Donald’s Dining Safari at Tusker House Restaurant in Disney's Animal Kingdom Park is another fun location to enjoy Character Dining for breakfast or lunch. Follow this link to view Table-Service restaurants that offer
Character Dining. You will be able to look under the name of each Table-Service location to see if Character Dining is available at that particular restaurant.
If you have your heart set on Chef Mickey's, I would suggest that you keep checking periodically to see if anything opens up. You never know when someone may cancel an Advanced Dining Reservation.
I hope this information helps! Please don't hesitate to visit me again if I can offer any additional dining recommendations or answer any other questions that you may have as your vacation draws closer. Best wishes for a magical trip, Janet!
Bon Appétit,
Jodie