Phuket is known for its nightlife (not exactly baby friendly) and beaches (depending on resort). Club Med Phuket has facilities for babies (baby club med) and they also have a babysitter so you and your husband can enjoy a snorkeling or diving session in peace. http://www.clubmed.com.sg/cm/resort-phuket-thailand_p-362-l-AE-v-PHUC-ac-vh.html
It is not really a baby friendly place. You can hire a personal driver to bring you around instead of taking public transports to go around the island. Also, you can book family hotels that provide kitchen facilities for you to cook baby's food. I booked family apartment from airbnb.
i wont say phuket is baby friendly. like the above mom said it's known for its nightlife. maybe go to bkk better option.
thanks