Can I sue now?

What is the name of your state? Colorado

My ex moved out before the lease expired. We agreed before she left that she would pay half the rent and half the damages if they exceeded the deposit. So far she has been very resistent in pay her half, going so far as to lie about bills she has comming up. I wanna know what exactly I can sue for at this time?
There are a couple of months left on the rent and there is a list of repair costs in the lease. Any help would be nice.
Thanks

is your ex on the lease?

Im pretty sure you can just take it up in small claims court.