Fourplex Tenant Management Advice

[Wade Garrett]

I just closed on a fourplex, and I am working out the kinks with tenants, leases, and parking. 

The fourplex is one 3 BR and three 1 BR's. 
For parking, I have a two car garage, two open spots, and a driveway. Enough for everyone. 

Currently, the largest 1BR pays $900 (market rent $1,100) and has half of the garage. She is on a month-to-month. 

The 3BR was promised half of the garage by previous owner, but never in writing, and the woman in the 1BR is difficult to share with. 

If I had it my way, the 3BR would have the whole garage (for higher rent). The 1BR woman is a pain in the ***, and I want her rent up, and her out of the garage. But I also don't want to ram up her rent and take away storage at first chance. I have a problem with it from a principles perspective. 

I am thinking giving her two choices: $900 rent, move out of the garage, or $1,025 to take the whole garage. 

Your thoughts?