It is my understanding that there is no proof as to the parentage of either Nathaniel, or Abiah.
There is proof to support the venture to say that none of Nathaniel and Abiah's children were likely born in Penn.... Abiah died and was buried in Jerusalem, Yates County, NY in 1803.
Nathaniel and son, Stewart/Stuart/Steward, were still in New York, as heads of households, up until after 1810 :
Nathaniel and son, Stewart, are in 1800 Jerusalem, Yates Co., NYhttp://www.yatescounty.org/upload/12/historian/1800.htm
CALHOON NATHAN 462 JER
CALHOON STEWART 462 JER
Nathaniel was in Jerusalem, Yates Co., NY, in 1810... he is the only Calhoun head of household... son, Jared is not yet listed,... no Cahoon or Cohoons, either.... but ... son, Steward is listed as Colhoun, in Benson :http://www.yatescounty.org/upload/12/historian/1810.htm
CALHOUN NATHL 174a JER (Jerusalem)
COLHOON STEWARD 146a BEN (Benson)
[Jared is not yet listed, as head of household, in 1810... only Nathl and Steward.]
Hope this helps.