Hi Tabitha!
Welcome to the Disney Parks Moms Panel! First off, thank your brother for his service to our country! And how fun that you're planning a super fun Walt Disney World Resort Birthday trip for your mom next year! I like that you're giving yourself a lot of time to resEARch every detail of your vacation.
Mine's a military family too, and we are so thankful for the way that Disney shows their appreciation for those who serve their country by way of the wonderful
U.S. Military Promotional tickets. The service member does need to be present when first redeeming these tickets. If purchased on base, the service member will receive paper 'Exchange Tickets' that will need to be validated in person at any
Guest Relations location prior to their first use. Military tickets may also be purchased through
Shades of Green, which is a Military-owned resort located near Disney's Magic Kingdom Park. Tickets would arrive to your house already validated; however, they would be assigned to each individual user and the Mil member would need to be apart of your party.
Another thought is your brother would not need to stay as long as your total vacation in order for you and your mom to benefit from the longest ticket option. Once the tickets are validated, you're set. This way your mom can see both of her babies on her birthday, and you two can stay and play. (You could even get a Military rate on a
Disney Resort Hotel room if he met you both on your check-in day.)
I hope this helped, Tabitha, and we'll see you in 2019!
~Kristen