Roommate Brought Family Members Into a Shared Home and They Don't Pay Any Rent

I've been renting a house in centennial, CO with 3 other roommates on the lease for about 4 months. From the start one roommate ("C") has had their mother ("G") living in the house without putting her on the lease and hasn't paid rent. About 2 months ago, C's brother ("E") moved in. He hasn't paid rent since he moved in. We all agreed that we would give him a few weeks to get a job and start paying rent but it's been too long for me and 1 other roommate ("A") now. We gave her mom a little time to save up and get back on her feet but it seems like she is permanently staying now. Can me and A hold roommate C liable for her family's free living? Or can we hold G and E liable for their share of rent that was not paid? Also are they considered tenants now since they have lived there for a certain amount of time?

Also I'll be leaving for school in a month so ill need to take my name off the lease if that is a factor in this situation.

Roommate Brought Family Members Into a Shared Home and They Don't Pay Any Rent