My question involves landlord-tenant law in the State of: Massachusetts
My roommates and I live in a university town in which subletting rooms is common during the summer and/or semesters. We found a subtenant for 8 months. Terms were verbally agreed upon (Jan- Aug), approved by landlords, but no written sublease was signed. The subtenant has now announced he/she was leaving early (and no attempt to find a replacement has been made). We searched on our own and have found a potential tenant. However, the tenant leaving refuses to move out any earlier than June 30, effectively paralyzing our ability to find a replacement (June-August is a standard time frame).

We sought out the the Mass Tenant/Landlord guide as well as the "How to be a good tenant without getting ripped off" guide, which intimates that tenants on a lease MAY have the right to legally evict a tenant not on the lease.

Do we have the legal standing to ask her to leave earlier?

Thanks so much.