I can say about Amalfi.
Probably not the easiest destination with kids.
Lots of stairs, up and downs.
Renting a villa is uber expensive and, more important, Amalfi and the whole coast are not made for the pure beach lovers, since the beaches are very small and not completely sandy.
In April weather could be comfortable, though not enough for a swim.
Just think at Amalfi (alike Positano, Ravello, Capri, Sorrento etc.) as a romantic getaway best suited for couples.
An idea to take in mind for a future celebration with your better half.