Thank you Suzanne,I did eventually figure this out!The paper trail is week, but DNA testing helped to confirm what I was thinking.
Mary Elizabeth (Eliza) Gallant who married Ferdinand "Frederick" Robichaud is the daughter of David Gallant and Eliza Gardiner. David Gallant is the son of Joseph Gallant and Dorothee Downing. Eliza Gardiner is the daughter of Bowden Gardiner and Ann Howatt.
The people related to Eliza Gallant as her baptism sponsors are distant cousins, but all born in the same area as her father, Rustico, PEI.