I'm sure they have 4th of July themed activities throughout the day.
We were there for Halloween and they had Halloween related crafts all day, costume contests, trick or treating, etc.
We were also there for Memorial Day and they had some patriotic crafts during the day and some other things (but I don't remember what they were.)
You could always call the resort closer to July 4th and see if they have the activities list for that day printed.