I think Kendra may have found herself the ideal man. He is athletic and handsome and barring a freak accident should have decades left to live. I am surprised she is settling down at such a young age, but good for her.
I always took issue with her grating voice and childish behavior (then again, she is really young), but I believe she had genuine care for Hef. I don't think there was hot passion between them, but she got a kick out of making him happy and she seemed to always be really grateful for the things he did for her and her family.
We can call her a whore and whatever else, but she saw an opportunity to live a life that was exceedingly better then the one she may have ended up having and she took it. Her 15 minutes may be up soon, but I am sure she had one hell of a time while she could!