Yes getting a report from the plumber would be ideal; however, I believe your issue will be no one knew that an open window would cause the pipes to explode. had you given them a notification the first time when it happened then you could say "Hey I explained to you this would happen" or have it written in the lease agreement.

If you didn’t steal her equity the easy out for you might be to just refi before it becomes a legal issue.

@Troy WelchThese two posts should address some of your concerns:https://www.biggerpockets.com/forums/51/topics/998718-explai...https://www.biggerpockets.com/forums/51/topics/1088325-expla...

I bought a house last year after inspection A general Inspection report showed everything is ok with the plumbing. nothing came up. last month I had some warer backout issue coming up from the bath in the basement, ordered a plumber. 

She's been there this entire time and i've had no issues; win-win-win!!!

I asked this specific question in this post and 2 accountants weighed in on the issue.

You will not hear from me about little maintenance issues.

is it worth offering discounts on rent and asking the tenant to fix minor issues themselves rather than calling the landlord, this to avoid property management company expenses? 

One thing I'd caution, the unit has been converted and it may cause issues in the future.

If you don't know your landlord tenant code, how to give proper notices, how long you have to fix maintenance issues, how to evict if needed, etc...you should hire a property manager