Lease-holder gone, lease occupant still on property

So we had a crappy tenant who didn't pay rent and we began eviction paperwork.  According to our other tenants, he's gone.  However his wife, an occupant on the lease, remains.  She swears up and down that she is merely moving her stuff out and will be  gone, but her full departure date keeps slipping. 

My question is, since  she is  not the lease-holder and is not paying, do I even need to legally evict her (along with her husband)?  Can I just call the cops and say she is trespassing.  I'm pretty sure she is just milking the situation, at least that is what experience tells me.