Congrats!!!!!
We are all getting exciting about the upcoming trip. I will be traveling with my 9 year old daughter, my 61 year old mother, a good friend and her 15 year old daughter again this year. We have planned to swim with the dolphins, have a zipline adventure, and horsback ride on the beach. I agree the ship excursions are rather expensive.
I used Shore Trips for our excursions. Our experience has been smaller groups, longer adventures, and great guides. Take a look at www.shoretrips.com. If you see something you like, register and book your excursions through them If you decide to go with them, I ask that you list Roxanne Lamb (me) as your travel agent. 
Good luck in picking your excursions and safe travels to LA.
Roxanne
RockStar Travels
www.rockstartravels.net