What will happen if she is late with rent or loses her job and can't pay rent for a few months?

Rarely do they like such units being operated in such way.

This will create your new basis.From an operational perspective, you might want to touch up a few things on the place to make it more rentable. 

Look for a market that is growing in population and jobs so that you can get in the way of obvious appreciation. 

Also, focus on 2 years of job/income stability.Class D Properties:Cashflow vs Appreciation: Typically, all cashflow with little, maybe even negative, relative rent & value appreciationVacancy Est: 20%+ should be used to cover nonpayment, evictions & damages.Tenant Pool: majority will have FICO scores under 560 (almost 30% probability of default), little to no good tradelines, lots of collections & chargeoffs, recent evictions.

Also, focus on 2 years of job/income stability.Class D Properties:Cashflow vs Appreciation: Typically, all cashflow with little, maybe even negative, relative rent & value appreciationVacancy Est: 20%+ should be used to cover nonpayment, evictions & damages.Tenant Pool: majority will have FICO scores under 560 (almost 30% probability of default), little to no good tradelines, lots of collections & chargeoffs, recent evictions.

It is hard and will be a full time time job to do it right. 

Quote from @Shiloh Lundahl: @James Wise Just like any model, there are good operators and bad operators.

Landlords mistakenly ASSUME all PMCs offer the exact same services and operate the exact same way, so price is the only differentiator.So, the first question they usually ask a PMC is about fees - instead of asking about services.This also leads them to ASSUME simpler is better when it comes to management contracts.

I will say that even though you get the boost from VRBO and AirBNB, the first year of operation is usually lean as you build up the rep.Offering a discount on the stay is a way to be more attractive but don't go crazy.