Should I Finally Kick Her Out on the Street?

Live together for 6 years, in our mid 30s - have ups and downs like everybody else. Have faced three times where she wanted to leave, but i've always believed in giving it your best shot before walking away, so its continued through those times. But each of those times also coincides with her finding a "special friend" for intimate liaisons. life never really recovered after the first incident. So, NOW, I just noticed the series of calls on the cell phone bill, the closed door conversations, out all hours with her 'girlfriends', and the soiled laundry (ewww!). She is supported by me and has yet to have a reasonable paying/steady job. Give me a reason NOT to kick her to the curb?!