Do I hold a rental?

[Brian Maroon]

I am a few weeks from finishing a rental.  A family called about another house that was already spoken for and asked if I any other properties. They came over yesterday to look at the house while I was painting and want to put a security deposit down to hold it and move in April 1st. I haven't even listed it yet.  They live a few blocks away from the house and want to move into mine. She called today and said they want to honor their current rent for March. They are currently renting from a friend. 

Do I hold it for them?