New Orleans....lets just say don't get near Bourbon street. Its just bars and strip clubs and the street smells like vomit and urine. The French Quarter is interesting is its history and the Garden district is pretty and historical too but your kids will get bored, and possibly you too. There just is not enough there to spend all of your spring break there. My humble opinion.
Have you ever been to Sevierville/Pigeon Forge/Gatlinburg? Tons to do and I gaurantee you will not see it all or run out of things to do in the amount of time you will be there. Your kids will love it. We moved here from Mich. almost 4 yrs. ago and love it. If you get tired of the city then you have the National Park to hike in. Weather is nice that time of April too.