Hi Hotdog
I can't easily see the marriage for them on SP. They were together in 1891:
Peter Kerr 27, Railway Carriage Inspector, b. Bishopbriggs
Grace Kerr 25, b. Glasgow
Margaret Kerr 2, b. Springburn, Lanarkshire
John Kerr 1 Months, b. Stirling
Address: 12 Bayne Street, Stirling
If Margaret above was first born daughter, would fit for the birth of Grace in 1863 with parents David and Margaret. If you look at one of the children's birth certs. on-line at SP, it will include a place and date of marriage for the parents (if married).
This looks a likely entry for Peter's birth from IGI:
PETER CARR Born 11 MAY 1863 in Cadder, Lanark, Scotland
Parents:JOHN CARR and MARGARET WILSON LOVE
Monica
