I have a tenant in a 2bd apartment with whom I recently signed a new lease. She was previously living there with a roommate and they were both on the lease, and I allowed the old roommate to move out and wrote a new lease with the one girl on the same terms. This is in a building I've only owned since Nov 1. When we wrote the lease, it was understood that she would be seeking a new roommate and I told her I was fine with that.

Now she has told me who she wants her new roommate to be and I'm not exactly thrilled. I've done a credit check and application for the prospective roommate, and she has pretty bad credit with multiple collection accounts plus a dog (she says her ex spouse ran up the bills) -- which would make 3 dogs for the apartment (current tenant has two very small dogs).

I'm struggling with what to do. On the one hand, I don't want to be overbearing and in retrospect, I did make her feel like she could pick her own roommate with not very much input from me.

On the other hand, I'm somewhat concerned with her choice of roommate and the additional dog. I did tell her there would be an additional $250 pet security from new tenant.

So, two questions:

• Should I tell her to find a different roommate? Downside being that it does make me feel like a jerk particularly since I wasn't perfectly clear from the start about not wanting another pet
• If I let her take on this roommate, should I add the new roommate to the lease (i.e., write a new lease with the two of them) or just keep the one lease with the existing tenant and make it clear to her that she is responsible for her roommates behavior, etc?

Thanks for the input, I do appreciate it.