My other idea is the Omni is Ashville NC. Weather should be mild and there us so much to do, you will easily be able to join in activities with your kids or let them do some while you chill in the spa or in a lounge with a good book and fireplace. If you can handle the drive, that saves you some money which you can apply to staying at such a nice resort

Arizona. Good weather and lots to do incl relaxing.

Fly in/out if Phoenix (the flight is direct from DC and hopefully not outrageously priced as it is spring break pricing).

I’d split time between Phoenix area (maybe Scottsdale) and Sedona. In Phoenix, see a baseball game, go to the botanic gardens, lots of area hiking. Sedona is stunning. The town is very cute to eat, shop and wander (my tweens loved it), there is even better hiking with gorgeous scenery, take a red rocks jeep tour.

In both places, stay at hotels with a pool and you can relax while your kids swim. I think there is a Marriott near Phoenix with a big water park and lazy river. I like the Kimpton in Sedona but that might be pricey this time of year. In both places there are enough hotels that you can price shop.

Oh, and do a day trip to the Grand Canyon - in your shoes I’d sign up with a day bus tour. It will be a long day but it’s a can’t miss sight IMO. My kids liked renting bukes and riding aling the rim of the GC.

Look at cruises

Traveling with two tweens and a near-tween and I've never gotten to go anywhere. Where's somewhere easy that I can take them mid-April if not for the whole week, for a portion of it where there are tons of things to do and maybe I can even relax a little? No passports, so much be in US. All in for 5-7k or less preferred