Smith & Wesson Engraved 1st model 2nd issue .22 (AH4025)

Smith & Wesson 1st model 2nd issue .22 caliber revolver. Bore is poor. However, the gun is well engraved, of the period. The barrel was silver plated and has traces remaining. The frame is nickel plated and has 93-95% remaining. The gun is inscribed "Maggie" on the backstrap. Action works perfectly. Manufactured approximately 1865. Charming 2nd model .22 caliber. Who is "Maggie"? Lady of the night or...?