I would check out that Isabella Stewart grandaughter's birth circa 1844.
Hmm - two possibles for age 7

Charles S/Isabella Currie = Isabella Stewart Birth:
23 AUG 1844 Melrose, Roxburgh, Scotland
OR
John S/Helen Cockburn = Isabella Stewart Birth:
02 APR 1845 Yetholm, Roxburgh, Scotland
Scrub that I don't think her name is Stewart check this one out ........
Isabella AIKMAN
21 JUL 1843 Lilliesleaf, Roxburgh, Scotland parents George Aikman/Margaret Stewart
She is the only Isabella listed within 2 years in Lilliesleaf whose mothers name is Stewart.