Always get a bill of sale, no matter what. It protects both buyer and seller, and prevents situations like this. I don't know what breed this horse is, but for AQHA, APHA, and those types of registries, you will be given her papers that are signed by the previous owner, or in this case, the person before the lady you got her from. Registries do not like skipping owners. If the new owner information on the back of the original papers is blank, you could just put in your info (although that isn't recommended), send the transfer fee, and you will receive the papers back in your name. If the lady you got her from filled out all of the information, just didn't send it in, or if you don't want to skip owners, you will need to get another transfer report (can usually do it online). She will have to sign as the seller and put your info as the buyer. You would send in the original papers selling to your friend, the additional transfer from your friend to you, and send in 2 transfer fees. This is how I had to transfer a paint I had. I would try to get the paperwork, or at least a bill of sale as soon as possible.