Tammy Sinclair (Previously Rowland) was John's rich yet naive and unknowing wife. Her father owns an expensive hotel.
It is revealed John didn't love Tammy as he tried to spark up another affair with Gabrielle. When Gabrielle was with John in one of the hotel bedrooms having an affair, Tammy interrupted them causing Gabrielle to hide in a suitcase. Tammy Later gets pregnant by John.
In Season Six, it is revealed that the two got a divorce.