These are Freeport PA McKees alright and there is a possible connection here if you know something about your James and Margaret Pierce McKee.
My Eliza (not Elizabeth) was the daughter of James John McKee (b. 1803, Down Ireland) and Mary Ann Crawford (b. 1817, Down Ireland).
I understand from World Family Tree resources available online there were eight children; Eliza (b. 1837), Nancy ann (b. 1834), Violet (b. 1843), Margaret (b. 1840), William (b. 1839), Isabella (b. 1849), Mary Jane (b. 1834), and James (b. 1845).
Do you know your James McKee's birthdate?If what I have listed here is in the ballpark then this may be the very same McKee family.I know nothing else about James.
That you are g-grandaughter of James' oldest child would appear to put this in the right generation to match.