Please help us decide which island to visit

We're hoping to travel to the Caribbean in January for about a week,
but really have no idea where to go... here's some basics:

*would like French speaking but not required
*really don't want an all-inclusive but it wouldn't be the end of the
world
*Family of 3 (mom, dad, 2.5 yo old) so need kid-tolerant but not
specific kid activities...she'll be happy with the sand and water and
a slide somewhere
*somewhere American airlines or Continental flies (since we're trying
to use miles)

I've been to St Croix in the 80s, my husband's never been to the
Caribbean. We're both pretty seasoned travellers and have lived in a
few different developing countries, are quite accustomed to non-luxury
environments. Not really looking for a 'sanitized' version of the
islands but we do have a 2.5 yo and don't want to be backpacking for
miles or dodging bullets...

We like to experience and explore local culture, local foods, local
life. Don't really need happening night life.

Any suggestions? I'm kind of at a loss as to where to start.

Thanks!