Suggestions for Short, Family-Friendly Spring Break Trip in April

Hi! I'm looking for suggestions for a Thursday to Sunday mid-April trip that meet the following criteria:

• <6hr flight from PHL or EWR
• We're taking our 6-year-old- and 2-year-old; they desperately want a beach/fun pool area. It's a birthday trip for the 6-year-old (who will just have turned 7)
• <$1200 a night on the hotel
• No Orlando/Disney - I don't have it in me to wander around Disney with a 2-year-old right now
• We're leaning towards staying in the US

Otherwise, we're open to location. I was considering two resorts: Fairmont Scottsdale Princess and The Breakers in Palm Beach, but we're looking for other options.