My mom has been renting a house for the past several years. She is on the rental lease. Recently she took on a roommate. They had a verbal month to month agreement but the roommate has not been paying rent on time and is several months behind on utilities. My mom has posted letters giving 30 day notices asking the roommate to leave. She refuses to go, and now owes my mom for 2 months of back rent and utilities.

a) Does my mom have to go through the courts to evict this roommate since the roommate is not on the lease? And since she's already given numerous 30 day notices?

b) If so, what if the roommate tries to pay my mom for the overdue rent and utilities in the middle of the filing of the eviction? My mom wants this roommate out of her house no matter what.

Thank you for your help.
I just feel so horrible for my mom. This has been going on for 8 months now and its unbearable for my poor mom.