Looking for any insight from experienced landlords.

We have tenant who is consistently complaining of maintenance issues, even once repaired, states that we took too long to address, "don't care about my families health and safety," etc.

The background (and there's a lot of it!): There were screens missing from some of the windows upon move-in which we authorized maintenance to replace (they were backed up several weeks due to COVID shut down), A/C wasn't getting the apartment cold enough even though it had been serviced within the past year (set at 68F during the hottest summer we've had in years in Michigan) and we didn't offer to pay her electric bill, found a bat in the basement x 2 which we had professional pest control there at their first available appointment and they didn't find any evidence of a colony but we had maintenance seal off any areas in the basement that could allow bats in, and now a water leak from upstairs apartment overflowing their toilet onto this tenant's mattress.  She has certainly had unfortunate luck since move in and we've addressed all complaints including being willing to replace basement carpet because of an odor that she states is present even though I can't smell it when I'm there and the carpet was professionally steam cleaned prior to move in.

With this toilet overflow issue, tenant's renter's insurance policy states that this is a structural problem and thus our responsibility whereas we feel that the upstairs tenant is liable for this.  Upstairs offered to have the mattress professionally cleaned, but tenant refused.  Now tenant states that she is sure there is mold between the ceiling from the water leak and that's why she is sick all of the time, accuses us of neglect and many other choice phrases.  I have all records documenting our response times and maintenance records from a legal standpoint should she choose that course of action.  There is no ongoing water leak and maintenance will be there tomorrow to assess and repair, within 48 hours of the initial complaint.  My question to you all is this: am I exposing myself from a legal standpoint by offering to let her out of her lease penalty free because she is not happy with the home or our service?  All 10 of our other tenants have been very pleased with us and how we operate our business.  We certainly will be doing a root-cause analysis of this situation to learn and grow moving forward.  She has 6 months left on her lease and obviously we won't be renewing, has been late once but is caught up and pays on time, she just complains constantly and drags every old maintenance issue up whenever something new arises.  I'd take the vacancy just to be done with the situation.