Hiya, Tammy!
How lucky to get to visit
Walt Disney World multiple times in the same year! I love visiting during different seasons and through the various holidays, and having an
annual pass certainly makes it easier to do so.
While you only need one annual passholder in your family to utilize the
annual passholder benefits, the best reason to have the pass is if it will ultimately be a savings in terms of actual theme park tickets. The benefits are subject to change at any time, and some benefits (such as room discounts) may not be available when you are planning your stay. If you are opting to purchase the pass not as much for the number of days you'll be visiting a theme park, but more for dining and shopping discounts, or those room discounts, and you are using the anticipated savings there to justify the purchase of the pass, then I'd say you really only need one.
The break even point varies on the annual passes, but as a general rule of thumb, if you include the free theme park parking and the free
PhotoPass downloads, you usually see the value in the annual pass in about 10 days worth of theme park visits. If the others in your family will be visiting at least that many days, it may be worth it for them to also have the pass.
May there be many magical vacations in your future!
Anna