I will be visiting the island next week and was wondering if anyone can give me some information on professional photographers who would take some family pictures for us on the beach. Thanks!

There are a number of folks who you could contact. I imagine a few will see your post and send you a private mail. If not, when you arrive on island you can make contact quite easily.

Susanna, who is the underwater photographer on the Woodwind, and also Dee are very good. Dee used to do wedding pics, but I don't know if she still does.

someone I would recommend and without single doubt is Marlis.
Photography was once her profession, now it is her obsession!
If I let anyone allow to make pics of me and feeling comfortable with, its her. she has a sails and canvas shop but I hope she does not mind recommending her as a photographer, stop by her shop and dont miss to ask her about her latest pics! Truly inspiring!
she is not the usual type of photographer, working always with the best gear on the market and loves details and perfect lightning.
As I stated, once a profession, now an obsession!
If I have questions regarding photography - she is the one that clearly can answer all of them. My personal bet is on her!
here is here contact link:
http://www.marlissailandcanvas.com/contactmarlis.html