Should I diclose in writing my relationship with the rental owner

[Patricia Luna]

Hello;

I am a new realtor in PA., and I am marketing my sister's property for rent. We do not have a listing contract signed and I am not being paid for this. I am representing her and my brother in law with a power of attorney. I have been verbally disclosing this relationship with all interested people who came to see the rental.

My question is: Do I need to disclose this relationship in writing on the application and lease? There is not an option that suits my relationship on the NAR. forms that I am using. I am not the landlord/owner, I am not an employee of the owner /landlord, and I am not an agent of the owner/landlord due to a property management or leasing agreement.

Thank for your time all input will be greatly appreciated.