Legal Question in Landlord & Tenant Law in Massachusetts

I assume the tenant pays electricity and heat. So unless you have a serious wear and tear issue the additional guest should not be a financial issue.

Moreover, you are not indicating she is "living there." They are entitled to have visitors on a regular basis and can have guests stay over occasionally. So other than voicing a concern about the visits and wanting to make sure nothing is done that will hurt the property and this is done with her consent, I would have a brief and friendly discussion with the Tenant.

Because your tenant is a tenant-at-will, you can terminate the tenancy for any lawful reason or no reason at all. If she is a good tenant, and it isn't causing problems, you may want to look the other way. If it isn't worth it to you, then evict her. We offer flat fee uncontested eviction services, and you should feel free to contact our office.