You will only be held liable for something if a) theres some liability on your part and b) you signed the agreement as a POA. If your mother signs it in her capacity as Admin then the Surrender Agreement should spell out all hold harmless language. You should have it reviewed by a qualified attorney. But no you will not be held liable simply for being a POA without actually signing the document. Its a good idea that you and your mom are on the same page and have a consultation to make sure your ok.
In general, in New York, an estate representative like your mother cannot delegate her duties. Therefore, your POA is ineffective for most intents and purposes. But since you didn't even sign the agreement anyway, the answer is "no", you cannot be held liable for anything relating to the Surrender Agreement.