There's a saying with horse racing gamblers ' follow the money ' - I would imagine on ancestry that term could mean, follow where the income, substances comes from by earning a living or income from something. Janet Isobel Brown was a Millinery (though she could have income from other sources) but what supported her in Canada, and Ivy in New York both places June 1900.
As for how Ivy travelled to the USA pre - 1900? you may never know, but you do know she did, from schooling years New York 1900 to later in Chicago (advise putting Ivy on the back burner for now) but concentrate on Janet in Canada may reveal more answers.