My Family Tree

Given the names of her children, and her date of birth, my guess is that this is her parents:
groom's name: Andrew Bowman
bride's name: Janet Robertson
marriage date: 14 Apr 1792
marriage place: Craigie By Kilmarnock,Ayr,Scotland

Citing this Record: "Scotland, Marriages, 1561-1910," index, FamilySearch (https://familysearch.org/pal:/MM9.1.1/XTKY-5X8 : accessed 02 Nov 2012), Andrew Bowman and Janet Robertson, 14 Apr 1792; citing reference , FHL microfilm 1041336.

Children born to Andrew and Janet Robertson in CRAIGIE BY KILMARNOCK,​ AYR,​ SCOTLAND include a daughter Agnes Bowman.

Name: Andrew Bowman
Christening Date: 07 Mar 1762
Christening Place: , KILMARNOCK, AYR, SCOTLAND
Birth Date: 02 Mar 1762
Father's Name: Andrew Bowman
Mother's Name: Jean Whyte
Indexing Project (Batch) Number: C11597-4 , System Origin: Scotland-VR , GS Film number: 1041386 , Reference ID: 2:16F09S9
Citing this Record

"Scotland, Births and Baptisms, 1564-1950," index, FamilySearch (https://familysearch.org/pal:/MM9.1.1/XTVG-4Y3 : accessed 1 January 2015), Andrew Bowman, 02 Mar 1762; citing , reference 2:16F09S9; FHL microfilm 1,041,386.

Jannet B. Humphrey was living with her son James in the 1881 census of PEI. She had been born in Scotland.