If she is having excessive visitors causing issues or more ware and tear on the property you may need to not renew her lease at some point.Remember you do not take anything anyone says at face value, not tenant or neighbours.

We have hotels where we had excess frontage land that we leased out.

This is what we look for regarding credit history.FINANCIAL/CREDIT HISTORY1.No outstanding debt to previous rental property owners.2.No outstanding debt to utility companies.3.No outstanding debt in excess of $1000 that is not in a payment plan.4.No excessive monthly financial obligations - more than 20% of income.5.Lack of credit history or marginal credit history may result in additional security deposit. 6.Derogatory credit (past due accounts, collections, charge off accounts, tax liens, judgements in excess of $1000 and/or bankruptcy) may result in additional security deposit or denial.

Water is getting in somehow and has to be stopped or moisture will just come back again.As a landlord you are not a mold expert.

I still think that a french drain system would help to channel excess water down to a city storm/sewer drain, and I'm thinking that as long as the backyard is not muddy, and the foundation of the house is not affected, then I don't worry about it, right?

I would be glad to refund if I had a renter sooner but they blocked me from entering the property without excessive drama.. this is besides the point.  

I would definately do a home and moisture termite inspection.  

From an Ins Agent: An Umbrella policy should be considered excess liability meaning over and above the coverage you already have.

@Alberto Murillo A gift in excess of the annual exclusion ($14,000 in 2017) would require the filing of a "Gift Tax Return Form 709" not Form 706. 

No excessive fees and the buyer gets to choose the home they want (FSBO or MLS) that HPA will pay cash for and then the buyer leases the home from them.