By water park I guess you mean Aquatica. Usually too chilly in November for swimming, but perfect for walking around Sea World. Gates open at 9, and park closes in the off season around 7PM. If you get there right at opening, and spend all day walking you can pretty much see everything, as the crowds will also be thinner than in summer, so almost no waiting or lines.
I think your kids are the perfect age to enjoy as well as appreciate SW. Stroller tykes (last week about one in 3 visitors was pushing a stroller) are too short for the rides, and their visit is mostly "I got splashed by a whale and got wet."
Your kids are tall enough so there are no limitations on what attractions your family can do together. More importantly, if any of your kids are into animals, or ecology, or conservation, or science, then seeing the amazing creatures (there are displays and aquariums

all over with things you are not going to see many places) is a fun as well as educational

experience. If their minds are starting to outgrow Plastic House of Mouse

Love, then SW can be a great place for them.
On the other hand, if all they want is instant gratification entertainment, then Universal and Busch Gardens have more roller coasters

and rides

. Although unless someone has a new one, as of a year ago Sea World's Kraken was still
Orlando's fastest, longest, and tallest roller coaster. (144 ft high, 65 MPH.) Busch Gardens SheiKra is the tallest coaster in the state (200 ft) and faster (70 mph) and the only dive coaster in the state and the tallest of the three dive coasters in the world. Yes, dive. As in completely vertical drop.
Thanksgiving weekend is very crowded at all the Orlando parks, but you say Mid Nov, so if you are a week before Tgiving weekend it should be medium crowds. My favorite time to visit a park is the first week in December. Smallest crowds of the year, beautiful weather, and the Christmas

decorations are up over at WDW plus it's Mousefest time.
Just tell them there's Free

Beer and they'll be ready to go.
Seriously, enjoy SW.
