A good friend of mine suggested I should take her as my tenant because what was perceived to be a prolonged softening rental market that is happening and extremely limited quality tenant pool. 

I have to ask, is the water softener a payment plan for the system for the home?

Not sure how long you have been around, but when markets soften, these types of assets get crushed because vacancy rates increase which causes condo fees to increase due to the amount of delinquency on the books.

However, if rents are softening where you are, then you may wish to consider negotiating with her.

In the current market environment I've been a huge advocate of seller concessions to soften the costs of financing, improve cash flow or limit down payments for other capital improvements (such as upgrades or furniture) but often (especially turn-key vacation rentals) come with strong buyer competition.

According to ResiClub analysis, “Multifamily rent growth has softened more than the single-family rental market.

It would also be important to try and understand why the settling happened- around here it is almost always a poor drainage issue that softens the soil against the house and over the years and decades can result in a settle corner or whole side of a home.  

Is the market softening?

The market has softened a bit now that we're past the high season. 

Balloon" framing (1920's I believe).Radon.Plaster and lathe instead of sheet rock (pre 1950's) or plaster and wire mesh variations (50's) more solid than sheetrock but a real b*tch to repair or demo if you're remodeling.You've got Galvy plumbing but also need to look out for other kinds of outdated plumbing like clay sewer lines (pre-1930's, prone to collapsing, bellies, root intrusion), cast iron (1950's, often rusted and/or cracked by now), and PB (polybutylene, gray-colored water pipes, 1980's, prone to rapid degradation and subsequent bursting, mostly gone by now).Buried Oil Tanks-- Do you have those there?