Hudson's might be nice. It's a seafood restaurant -- but towards the mainland from the resort. It's not too fancy, very kid-friendly, and has great food -- the absolute BEST hushpuppies!! Not sure if they're doing anything special for Easter. Normally they don't take reservations, but maybe for a holiday they do?
Some of the larger hotels (Westin, Marriott, etc.) have buffets and I'm sure they will have them for Easter dinner.
I think the resort may be doing an Easter dinner that can be delivered to your room, as well. If you haven't received something in the mail, give them a call. They do a great job with these!