Maybe she belong to Annie? and was a granddaughter of Robert and Esther? Sometimes cousins and nieces were entered as daughters.
Here is something from the Home Children site
http://www.collectionscanada.gc.ca/databases/home-children/0...HARPER
Given Name: Annie
Age: 10
Sex: F
Ship: Sardinian
Year of Arrival: 1888
Departure Port: Liverpool
Departure Date: 13 April 1888
Arrival Port: Halifax
Arrival Date: 21 April 1888
Party: Miss Rye's
Destination: Niagara-on-the-Lake, Ont.
Comments: Miss Rye's Party of 113 females to Niagara-on-the-Lake, Ont. Mrs.Heath & Mrs.Soffe were matrons.
Source: Library and Archives CanadaReference: RG76 C 1 bMicrofilm: C-4513 /4Type of Record: Passenger Lists Group of Children Traveling Together
I don't see a marriage for Jack/John Rowley to anyone named Annie who fits.
Cannot find any birth with them listed as parents.
Death site to 1934
Marriages to 1924
Births 1909