I run a tenant’s credit once on NTN or SmartMove and use that same application for many places within a 60 day period (until they’re accepted) vs having them pay $35-50 per adult PER house.

You are following the terms of your lease, she's an adult and if she wants some shelves, she can buy some free standing ones herself.

Nobody should be incentivized to do their basic required task, which in this case, is pay for their housing like the rest of us adults.

Landlords rule in this current market, at least in most of Southern CA because half of the adults can't afford to buy and there is still a housing shortage.

If their background is terrible, give your current tenant a written notice about how your lease does not allow adults not on the lease to reside there longer than 14 days in a calendar year (you do have that on your lease right?).

In Texas there are bylaws that do restrict the numbers of unrelated adults that may occupy a single dwelling (6) per City Code as well as no more than 3 times the number of adult tenants per bedroom per Texas Property Code.  

I'm redeveloping a 138-unit former senior housing building in Detroit into 100% affordable assisted living facility with an adult day care on site.

I would assume Round Rock is pretty close to Austin rules, but per City Code:City land use code allows no more than 6 unrelated adults per dwelling.

My wife and I raised our three grown adult daughters in my house.

Most importantly, try and carve out a space where the adults can escape.