You could have a look
here it's on a great beach and there are 3 flights with VS and 3 with BA weekly.
Alternately,
this gets pretty good reviews and the island is gorgeous.
Finally, I can highly recommend
this hotel on St Lucia the food is great and your wife will love the treatments; drawback is the long ride from the international airport. If you fly to ANU and get a connection it takes you to Castries airport, about 10 minutes away.