Hi Vicki,
Yes, you are more than welcome to wear shorts in the pool if you wish to be a bit more modest.
All Star Music Resort is so much fun and relaxed. You and your daughter will enjoy your rocking swim at the guitar-shaped or piano-shaped pool.
Since your vacation will be within April, you will be sharing it with others on spring break. March and April are the months when many families visit Walt Disney World for spring break, so you will experience the spring break crowd during most of your trip. You may see the crowd subsiding during the last few days of your vacation, though.
I hope this answered your questions, Vicki. If you have any more questions before your vacation, feel free to ask us at any time. We're always here to help.
Have a fantastical Disney day!