Lease is up 9/30. Not paying anyway. Should i evict($500.00+) or just hope she leaves

[Alison Decastro]

I have a "sometimes paying" tenant who hasn't paid July or Aug now.  Her lease is up 9/30.  If I evict it will take probably 6 weeks  and at least $500.00. 

I really just want her to leave, but I worry that she will stay after her lease is up. Is there any way to guard against her 'squatting'?