In Quebec, can I evict my roommate if I'm the only one in the lease?
At least in the US if your the only one on the lease and you didnt have a sublease with your roommate yes, in fact if your lease didn't allow you to sublease, they should not even be there. You could still evict with all the subleases in the world if they were not living up to the agreement. But, if no sublease, you might just need to ask her to find another place, no eviction needed.