Hi Gloria!
Reunions on their own can be so wonderful, but celebrating in Walt Disney World brings them to a whole new level! How exciting to be gathering with 25 loved ones. Although you only requested information on tickets, I'd highly recommend contacting
Disney Group Rates at (407) 828-3318 to be sure you haven't missed out on a special deal they might be able to provide you on blocks of ten or more rooms and tickets.
I do know of several authorized ticket brokers, including AAA, who may be able to offer discounts on bulk theme park tickets. I'd begin by contacting your local AAA travel office to inquire.
Undercover Tourist is another reputable ticket broker, easily accessed by a quick google search. Even more so, subscribing to the newsletter on the unofficial fan site mousesavers.com will currently provide you a bit of savings on your undercover tourist ticket purchase.
Customizing your reunion becomes effortless, as Disney offers many celebratory options like
Disney Family Portraits to commemorate your family time together.
I hope my answer was helpful to you, Gloria, and please visit us again with further questions.
I wish you MAGICAL "Disney Time" with your family.
Sherri