I don't know of Eleanor, but she could be connected to someone I have been trying to learn about:
John Porterfield married Sarah Unknown, November 1742 in Georgetown, Me. Sarah Unknown came from Parish of Raphae, Donegal County, Ireland. Sarah was born 8/13/1722. This John would be the same generation as your Eleanor. Sarah's story can be found in Henry White's "Early History of New England" published in 1841, on page 204.
John and Sarah had other children: John born December, perhaps 1743. Martha, born 7/18/1745, may have married John Foote. Margaret, born 5/14/1748, married Arthur Percey 4/23/1786 in Georgetown, Me.. Mary, born 12/26/1750, married Samuel Todd on April 14, 1773 in Georgetown, Me. They had a daughter and two sons. Daughter's name was Elizabeth, first married Unknown Woodwell, then married Capt. Benjamin Donnell. Sarah, born 10/21/1754, married David Hutchins 5/18/1777 in Georgetown, Me. Had a daugher, Sarah Hutchins married John Spinney of Long Island, Georgetown, Me. James, born 6/25/1756. Janet, born 6/27/1759.
The family lived near Parker Head and is so marked on the 1750 North map and then later on Cox Head at Porterfield Creek.
John Porterfield could have been a brother or cousin of Patrick of Thomaston.
John is listed as one of a group of men who organized a Presbyterian Church at Pleasant Grove in Georgetown, Me, now Phippsburg. This was in 1736.
If you make a connection to these names. let me know. My Porterfields lived in Pennsylvania at the same time, probably all from the same family of Scotland, later County of Donegal, Ireland, then on to USA.