My agent would say all adults over the age of 18...regardless of marital status.

Depending on your market (and I know nothing about your area) you may consider facebook groups for students or marketing anywhere students/young adults can find you. 

Nobody has a pool in their homes so #1 it is an anomaly #2 guests can enjoy the pool year round#3 kids don't care how small it is#4 there are adults who want to enjoy a heated pool, but feel self conscious in a bathing suit in front of others at a resort pool, now they have a private pool they can use with their family and not have that issue.  

@Eric Boshart...this type of financing does exist by specific DSCR lenders, but you're going to be limited on LTV and there are nuances with what constitutes adult care facility. 

Hey guys, I'm 17 years old but I have been JV with other wholesalers and have a trusted adult sign off for me.

The adult daughter makes about $1600 per month.

guests=1&adults=1&...

Landlords cannot evict tenants or threaten to evict victim tenants for domestic violence, abuse, or sexual assault.

If more than one adult is in their part, I don't start screening until every adult has a complete application.

Other family will typically step in and help you out.If you've got the money to buy, just find an older adult in your family, and make the pitch, "Hey, I'm looking to invest in real estate...