Lets shoot for $90k down, $150k gross per year, adjust for your COC calcs, once you throw in expenses, Debt/Interest.  

I know these types of deals well as I've done over 60 of them in the last 12 months working with out of state investors.These will rent for $1,200 - $1,300/mo and your costs would be:- Mortgage payment = $499/mo- Property taxes = $200/mo- Property management = $120 - $130/mo (10% gross rents)- Insurance = $75/mo- Capex/vacancy/repairs = $180 - $195/mo (assumes 15% gross rents)- Interest payment on HELOC = $187.50/mo (assumes interest only at 9% for $25k borrowed)Total costs = $1,261.50 - $1,286.50On the low end of our rent range you're losing $61.50/mo.

Her gross income is $125K/year (thru two jobs).

But understand the type of risk could be the exiting tenant having poured cement down the drains, no appliances, no cabinets, a leaking roofs with mold inside the house, no AC,  or squatters having lived in the house with untold 'grossness' being left behind for you.  

So, I would either work this through your brokerage if they do property management, OR you could become a W2 employee for the current building owners to manage their property without it impacting your license.

Also you can save a lot of money if pm has their own handyman employees and do not need to sub out all repairs. my experience is that STRs outperform LTR by enough to cover the PM fees, utilities, and additional furnishing costs but not much more.  

We calculate rent plus all debt payments as a percentage of gross monthlyincome.Our underwriters strive to analyze and balance all the information above to determine the statistical likelihoodof a tenant paying their rent on time.ApprovalOnce an applicant is approved, we require a nonrefundable Holding Fee to make sure they are serious and don’tchange their minds.

Do I have to pay an employee a mgmt fee (myself?)

The singlewides would be roughly 1000/month gross rent each ($4000 total).

My pockets are not deep, and I am a W2 wage employee part time RE investor.