If you have the owners approval and cooperation, there is no reason why you cannot collect a fee if the seller wants to pay you one. There is no law against two people entering into an agreement as long as the terms are for a legal purpose. Of course, your question assumes that you are not pretending to be an agent and the seller knows up front that you are not an agent, and any buyer you talk to would also understand that you are not acting as an agent.
The seller is not bound by real estate license law unless the seller is an agent or broker him or herself. A private owner may take whatever actions they choose to sell their property. They are not bound or governed by the laws concerning referral fees to unlicensed individuals.
Licensees may not pay referral fees to unlicensed parties, but this would not have any jurisdiction over private property owners who are not licensed.