hello!!!!
you know me too well.
baby jumping on my cervix, sleep impossible.
tobago - coco reef. direct flight, 10 mins transfer from airport, big, very shallow shelving protected bay with white sand, super duper child friendly re food etc, tobago a v pretty island (CD also a fan). Other places to stay there - plantation villas (rent a 3 bed villa on a fab beach, there are about 6 arranged around a communal pool). Useful if you are bringing own babysitter (mother, nanny) or going with other couple/small family, but might be too big for just the three of you. On no account be persuaded into the Hilton Tobago - godforsaken empty conference style hotel. But they make it look OK in photos. Also generally avoid anything that starts with "Rex" in the Caribbean, unless you are willing to go very cheap and cheerful and DIY, but on OK beaches.
otherwise - you need to go to one of the direct islands - so that reduces you to barbados, antigua, st lucia, [jamaica - wouldn't rush there so in sq brackets].
st lucia - the v family friendly place is windjammer landing but I don't like the look of it. have been there but not stayed. in the north of the island which is the least pretty most built up most cruise shippy bit. beautiful bit is the south - the jalousie hilton looks nice but once there you are there if you know what I mean. And a LONG t'fer from airport in the north unless you go by chopper. will be more expensive than coco reef I think.
antigua - lovely beaches, nothing in the middle, they ahve abandoned all pretence of earning any money from anything other than tourism. There are some OK places there, most of them pretty tired (St James Club), or super expensive (Curtain Bluff). I'm out of date on antigua really.
Barbados - have a look at Little Good Harbour (I've put a LONG review of this on here somewhere, have a search). Don't be tempted by Glitter Bay, they are about to start a very long needed refurb. Most other hotels either v expensive and glitzy (on west coast) or horrible (on south coast). But there are some good villa complexes - look at Emerald Beach Villas (2 bed, good value, fabulous beach, nice communal swimming pool, good restaurant).
Hmmmm. Def look at Coco Reef, but check Trip Advisor, I was there about 4 years ago and it may have changed/gone downhill since then.