At MK your DD will be able to ride more things than she won't be able to ride. The only things she won't be able to ride are the rides with height restrictions like:
Space Mountain
Splash Mountain
Big Thunder Mountain Railroad
Goofy's Barnstormer
That's all that I can think of right now...
At AK she will only be able to ride Kilimanjaro Safaris, Triceratop Spin and the train to Rafiki's Planet Watch/Conservation Station. AK is a beautiful park with lots of trails to explore so you definitely won't run out of things to do.
Here's what I found out about tickets:
One-day/One-park ticket -- Provides one admission to your choice of the Magic Kingdom Park, Epcot, the Disney-MGM Studios, or Disney's Animal Kingdom Theme Park. Valid for admission to one theme park only. $58.31 for adults (includes tax) and $46.60 for children ages 3 to 9 (includes tax) (3/04) This ticket does not allow park hopping.
2 Day/2 Park OR 3 Day/3 Park ticket - These are the tickets that were originally known as "bounce back" tickets when they first came out. You can only purchase the 2 day and 3 day passes at a WDW theme park ticket window, any Guest Relations location, any Guest Services location or at any Disney Resort front desk. You can not purchase them over the phone, at a
Disney store, at any Disney off property ticket source, or online. These tickets allow entry to only ONE PARK per day. They do not need to be used at the same park both days. You cannot park hop with these tickets but you can leave and return to the same park the same day. Be sure to get a hand stamp before leaving.
2 Day/2 Park ticket - Adults $111.30 (includes tax) child, $87.86 (includes tax) expires 4 days from *purchase*. (3/04) You save $5 off the price of two single day tickets.
3 Day/3 Park ticket - Adults $164.28 (includes tax) Child, $129.13 (includes tax) expires 6 days from *purchase*. (3/04) You save $10 off the price of three single day tickets.
You can check this site for more info:
http://allearsnet.com/pl/ticket.htm
Have a great time!!