Who is Tina from Skin Tight and what is their importance?

Tina is one of the three sunbathers that Stranahan finds trespassing at his stilt house. She is a model with a superb physique which Stranahan tries to persuade her needs no cosmetic improvement. She and her boyfriend are often out on the water in Biscayne Bay and it is they who rescue Christina Marks and the other women from Stranahan's "party" after their rental boat breaks down in the bay.