I think the roommate should be evicted.
I assume someone is paying, for electricity, so everyone who lives in the home is going to get electricity.
The landlord, or landlady should be billed, for certain utilities that everyone will use in the home such as electricity, and water, etc. Everyone who lives in the home should pay, for it either before, or once the landlord, or landlady receives his, or her bill.
I assume she is using water, and electricity, so these are utilities that should be included with her rent. In other words it's not a good idea to say utilities are separate in a shared accommodations home. I think whoever says that would be making a mistake.
I suggest the roommate looks, for a new home that does not have utilities. I think this is going to be difficult, or maybe impossible, for her to find if she looks, for shared accommodations. She would have to look, for her own home, so then she can decide what she wants, and does not want to pay, for.