I had some spare credits, so had a look on S.P. to see if I could find anything....
If Catherine's age on the 1891 Census was correct, it would make her year of birth 1882 +/- 1 year
On S.P. there are only two Catherine Gillespies born in Stirlingshire in the Falkirk area. The first one:
(Born 10th August 1883 at Kerse Lane, Falkirk to Patrick & Bridget Gillespie m.s. Gallacher.)
The second one was born 1883 in Polmont - I didn't look at that one
Changing the year of birth to 1890 +/- 1 also only brings up one and again, another wrong one.
(Born 1st March at The Thorn, Parish of Falkirk to John & Mary Gillespie m.s. Taylor)
Anne