Renting out to 3 adults

[Ashish Wa]

Hello,

I am a first time landlord and have been struggling to rent for 3-4 months. Not a lot of applications but rejected some out of caution. So this couple that now wants to rent has a service dog. Initially I wasn't really keen in renting to a family with dogs but since I do not have an option, I am thinking to proceed. Hoping service dogs are better trained. But they also want their brother to live with them. That guy also have a different last name. How do i proceed with that? I wouldn't want to loose this lead but also do the right thing. The couple has seen the house but the brother wants to see it now. Should i tell them that its going yo be extra $200 for the brother since he doesn't seem like a brother due to a different last name? Please suggest

[Ashish Wa]

Quote from @Theresa Harris:

The brother could have a different last name for a few reasons-different dad, the brother of the wife.  Do background checks on all 3 and make sure they all meet your rental criteria in case the couple move and the brother stays.  I'd double check that it is a service dog vs an emotional support animal (pet with papers someone paid for online).

What is the rationale for charging more rent?  Are utilities included?  I wouldn't charge more for rent if it was a family of 4 vs a couple or charge less if it was one person in a 2 bedroom home. I am renting the house based on market rent, not how many people live there as tenants pay all of the utilities themselves.

Appreciate your response. Yes brother will submit a application for himself as well. I read some post on BP where they were suggested to charge more rent for 3 adults, but if that's not okay I'll not do that . 
Regarding the ESA, they shared the document with me. How do I check/confirm its legit and not something that the owner just paid for online?