1860s CDV Erie Pennsylvania Group, Woman in Mourning Dress Civil War Tax Stamp

  
Original CDV of a group of four young people, the seated woman wearing a mourning dress and holding a handkerchief or letter? Note that the standing girl next to her has very similar facial features, and was probably the seated girl's sister, but she is not in mourning attire... Which is why I believe it was likely a boyfriend/husband. On the back of this CDV is an Erie, PA studio imprint and a cancelled 2-cent Civil War revenue stamp. Very good antique condition overall..