Is her loan for the trailer only, is there  a separate loan on the lot?

If two, I'd also look for an area where your two markets are separate, but where there can be some overlap for referrals.  

Although sometimes the parties sign docs at separate times.

Not good times for AC, the city has to do something to separate itself from the competition because at the rate it's going it will be a shell, see Detroit. 

Like anything real estate related you need to be highly educated before you dive in lest you be separated from your hard earned money

The problem is at some point the duplex was split and is separately owned.

Their website says it is a separate transaction.

Cleaning is a sore spot because as Jon says, most form leases say "broom clean" and unless you have a separate cleaning/turnover fee in your lease, you don't get to charge them anything more.  

With two years I could do all the work myself making the separate entrance and all the work needed. 

The problem here is I will need to use a property manager, thus reducing my monthly profit.I'm interested in the FHA route, but it seems tricky since I'm unmarried but not planning to live separate from my boyfriend full-time.