Anne, I do have records indicating that Elisabeth Walker was John Reid's mother (and Elizabeth Reid-Gemmell's). William Reid, her husband, died early in 1851. In that year's census, Elisabeth Reid (age 50) is listed as living with children James, Mary and William and some boarders, one of whom is 5 year old Matthew Gemmell! In 1861 she is also living with 2 sons and 15 year old Matthew Gemmell, among some other boarders. I can't think what the connection is, but there must be one.....
So Aunt Elizabeth Reid Gemmell was perhaps living in Rankine Street, Johnstone and Caroline living with her just prior to her admittance to the poorhouse in 1872? Or maybe Auntie Liz was just the person who brought her there to have her child. Hard to tell unless 1871 records magically surface and I haven't been able to pin those down yet!
K