In RE investments you'll have unexpected expenditures. 9\below 10%CoC and 167k for a duplex seems high in my opinion ($900/unit).

R&M at $250 per month but not any tenant turn costs or capital expenditures. 

You will still have possible vacancies, maintenance, capital expenditures, HOA fees that always go up and never come down, etc.Since it was fully renovated, she may very well have low expenses for many years.

They probably could use the money for her burial.  

Our understanding is that this is consider a Capital Expenditure and if gets depreciated over a period of time.

Each of these will save me headaches in the future, but once you start adding these up, you've got some real expenditure going on!

Don't forget to put away for capital expenditures especially if you're plan on keeping the property long term.

Make sure you're covering all expenses and saving for capital expenditures for the "long term game".

I would like to know if it's realistic to use 8% for repairs & maintenance , 5% vacancy( hot area in Florida), 8% capital expenditures and 6% management fees ( in house). 

That alleviated my concern about a failing unit while protecting my wallet from an unnecessary capital expenditure.