While it's almost never worth pursuing past rent, it enables tenants to keep doing this to other landlords.

Unfortunately if you signed an exclusive right to sell with the agent, then it probably says that even if you procure a buyer on your own you will owe the listing agent the 6%.  

I tenant will not move for a 10 to 25 increase in rent.  

Being a tenant rep or landlord broker for procuring tenants and getting leases signed.4.

You're really going to need a handy man and a realtor.You can hire the realtor to procure the tenant, for a finder's fee.

@Ken Thom @Nathan Platter is correct provided you are not procuration a property with a deed restriction.

You need something to protect you against all the eventualities - like another broker stepping in and claiming "procuring cause" for the buyer.I'd talk with your broker and get an attorney to draft that agreement.   

The COC ROI will be 14.88% and the monthly cash flow will be $535.95 after subtracting for vacancies, repairs, cap ex, taxes, insurance and P & I. Tenants

Tenant shall provide a certificate of insurance to Landlord demonstrating that Tenant has procured the required insurance coverage, within ten (10) days after the commencement of the Term of this Lease and within ten (10) days after any renewal or change in such insurance coverage.

If you were unlicensed when she brought the property to you, she is likely due the buyers side commission under procuring cause.