St. Kitts beach for family

Can someone recommend which beach would be best for a family? I have a 4 yo who loves to play in sand and a 7 yo who loves to swim but prefers mild surf. I will also have my 70 yo mom who wants a beach chair but loves sun and a nice walk along beach. Bathrooms are preferred but don't need anything fancy. We only stay for 2 hours or so, thus food not that necessary.

Thanks for any recommendations.

The closest beach from the port is Frigate Bay, has everything you are looking for. The next beach over is South Friars, beach is nicer, again mild surf. The nicest beach is Cockleshell Beach which is the furthest away from the port. (approx 25 min. each way by taxi).