Credit score policy for adult child to be put on lease?

[Bob R.]

I'm doing some rehab on an SFH that we're about to put on the market for rent.

A friend of ours told us about a friend of theirs and recommended them to us.  The potential tenant is currently renting a home and has been in good standing for 4-5 years.  The owner of the house died, the house is criminally underwater, deed transferred to unsuspecting ex-wife of owner and she plans on letting it foreclose since ex-wife thought she had nothing to do with this house any longer.  The tenant started making her rent payments to the ex-wife upon the landlord passing.  ex-wife has been taking them and basically warning the tenant "I don't know how long you'll be able to stay here"...

So in any case, the tenant is on the hunt, and we spoke with her about our place coming on line and its in a neighborhood near hers.  she's excited because rental inventory is low around here.  

She is a single mother with an adult daughter that has just graduated high school and i think will be going to community college.  From talking with the friend who recommended her I don't think there will be any issue with income/credit/background check (the fact that she started paying the ex-wife in the above scenario was a gold star in our eyes).  I think she could end up being a long term, low-fuss tenant.

We've never rented to anyone with an adult child lik ethis that we intend on getting an application from and running the background check and standard stuff on both and putting them both on the lease.

My question is do you hold the adult child (or any other adult co-applicant in other scenarios) to the credit score limit of your criteria??  I'm pretty sure the kid doesn't have credit history...