Im not sure about actually living in the mansion but as far as being a "Playmate" most are around an average age of 22, there are some women who became Playmates in their 30's. Rebecca Anne Ramos is the oldest Playmate to date, appearing at the age of 35.
But here's the sad part its not that they "kicked out" for someone reason playboy bunnies die young!!
R.I.P Jayne Mansfield (34 - car accident), Linné Ahlstrand (30 - cancer), Paige Young (30 - overdose sleeping pills), Claudia Jennings (29 - car accident), Tonya Crews (28 - car accident), Elisa Bridges (28 - drug overdose), Sue Williams (23 - suicide), Willy Rey (23 - overdose sleeping pills), Carol Willis (20 - car accident) and Dorothy Stratten (20 - murdered by her husband) all died young.
I know Hef did get sued last year tho for firing his Mansions guest realtionships cordinator for being "too old" but she was 47 and replaced with a 33 year old.