Quote from @Sami Gren: I start by making the original tenant fill out a form requesting to add a new renter, and they pay me a $50 processing fee (I charge a $50 fee any time I make changes to an existing lease). 

., to be honest, if you can't simply explain it in a post, you have already lost a vast majority of investors.  

Either way if it helps someone out especially going through what he mentioned it may add some gratitude and help him avoid further late bills.You can get more bee's with honey so in some cases it can pay off being a little more lenient. 

How do you think the 2 relatives will feel about having their rent raised or being required to pay rent period?

It was like paying for multiple Master's degrees to get our "real world" experience.  

Hopefully you can state simply (and truthfully)  at the end of the showing that you have other interested parties to whom you are showing the property and will let them know in due course.  

If you have a lender they should be getting lien releases as they pay draws.

Investment Info:

Single-family residence fix & flip investment.

Purchase price: $58,500

Cash invested: $55,000

Sale price: $155,000

Contributors:
Peter Vekselman

Partner Drive...

I liked the tenant, school is starting back etc, I told them they could pay first month and security deposit and I would let them have the rest of August for free.

Now understand, I am not picking on you, I am simply explaining the process you are going  into.