@Jason Ma I would suggest looking at a different market if you have exhausted every opportunity.  

In short, when opportunity (and a ghost) knocks, Raise the Roof with an over-the-top haunted house party, and then Raise the Rent!

First I could collect all of your evidence and present her with a number with the opportunity to rectify.

But here in the USA, for a long time, I pursued other things I saw as business opportunities.

Plenty of fix and flip opportunities in both residential and commercial still exist.

I'd offer them the opportunity to have the lease amended to account for the pets (with pet rent) or the opportunity to break the lease and find somewhere else if they don't want to pay the rent.This gives them the choice and you a chance of not having to deal w/ turnover/eviction.

I have an opportunity to buy my grandmas property at 341k and is valued at ~400k. 

Think there are opportunities everywhere if you know how, where, and what to do!

That is a given in your market.No problem in speculating, provided real estate market does not adjust down but expecting positive cash flow on this property is a joke.The opportunity value of your equity (10%) alone is costing you 8K per month in lost income.

Thanks,Congrats on your pending sales sounds like you have some exciting opportunities in your future.