I posted this to the Wiki profile manager for Margaret which had several errors.
Several corrections.
John and Anna Barbara had a daughter Elizabeth born 3 Mar 1787, the date you give for Margaret. But Elizabeth married John Heckman. Here she is on find-a-grave.
https://findagrave.com/cgi-bin/fg.cgi?page=gr&GSln=heckman&GSfn=elizabeth+&GSby=1787&GSbyrel=in&GSdyrel=all&GSob=n&GRid=30661829&df=all&The woman you are profiling was mainly known as Margaret. That was her name in her father's will, in the 1850 and 1870 Census (and as M Hartman in 1860).
However, it does appear she was Eliza M at times -- using sources including the death certificate of her daughter Margaret, her tombstone (see link), and a Cass County biography on her son Kleckner Hartman (see link, you have to scroll down to find him).
https://www.findagrave.com/cgi-bin/fg.cgi?page=gr&GSln=HART&GSpartial=1&GSbyrel=all&GSst=24&GScntry=4&GSsr=4281&GRid=25546941&http://www.migenweb.org/cass/biographies/cassixha.htm Both her tombstone and the Cass County article also give her birth year as 1795 which of course makes more sense since Jonas was born in 1796 apparently.
And if that is the case, then she was born, not in Northampton (only 1 "h" by the way) County but in the Mifflinburg, PA area where the family had recently moved. Mifflinburg is now in Union County, PA but would have been Northumberland County when the Kleckners moved there and when Margaret was born.
I manage the Wiki profile of George Kleckner, my ancestor and Margaret's brother. I've not connected him to his mother since, while her profile is OK, the Wiki profile on Anna Barbara's father is suspect in several ways and I haven't yet decided to spend the time and possible energy necessary to get it corrected.
Are you a descendant?