Twiddling my thumbs on a miserable wet day so thought I'd try and see what could be found just using the free indices on Scotlandspeople along with the 1901 census on Ancestry. Here is what I came up with-
Only one Margaret Russell age 7-8 in Clackmannanshire in 1911
Using the second person forename option in the 1911 census index on Scotlandspeople discovered there was a John, Jessie and William in the same household. Used the same index to work out that John was age 39, Jessie age 32 and William age 6 so looked as if the parents were John and Jessie. No obvious married couple in Clackmannanshire in 1901 census so looked for a marriage between a John Russell and a Jessie and found one in Alloa, Clackmannanshire in 1902.
Looked at all girls called Jessie born in 1879 who were living in Clackmannanshire in 1901 and noted surname ( there were six). Tried each surname in turn in the 1902 marriage match on Scotlandspeople. Came up trumps with Jessie Fyfe.
In 1901 there is a John Russell born 1872 living at Kennet, Clackmannan, son of William and Hellen. According to Google Kilbagie Mill was located a Kennet so a possible good match.
There are two girls called Jessie Fyfe of the correct age in the 1901 census- Jessie P Fyfe living also at Kennet (daughter of Thomas Fyfe) and Jessie H H ( daughter of John Paterson Fyfe) living in Alloa. My money would be on the former although the Alloa marriage might link to the latter.
All of this might be a total red herring but possibly a place to start with your search.
Isobel