Ok, put on my thinking cap and I think the property that is right on the beach is the Royal Mauian. I think it is on Kamaole Beach Park II. The pics on the following sites seem to confirm that for me. Personally, I would go with the Kamaole Sands with young children, just nicer grounds, not as expensive, beach etc is nicer too.
You can go up to the Royal Mauian and use the beach there if you so desire anyhow. The beach there is public.
http://www.mauisunshinevacations.com/royalmauian.htm
http://www.tripadvisor.com/ShowUserR...ui_Hawaii.html