The co-signer is under no obligation to be held accountable. All contracts must have a date of beginning and a date of ending, and it mean just that, ENDED.
If it goes to court, your friend will win. How convenient that the apt manager said "they just roll it over", no notice to your friend and no opportunity for her to opt out???
I am a property manager, and have many roll overs, the lease is for one year ONLY, from then on it is simply a MONTH TO MONTH, tenants can move/break the lease anytime with only a 30 day notice after the first year.
thank you, annie!