Hello Suds,
the image does read Mrs John Ballantyne but has been indexed without a forename. To find it, enter only the following on the 1861 census form:
Surname Ballantyne
Age range 32 to 32
County Glasgow City
District Bridgeton
This will return only one result, which is your person. Unfortunately, the family crosses pages with the youngest on the second page.
Regards,
John