Likely entry for them after their marriage in London:
John Jackson 24, soldier b. Scotland
Bessie Jackson 24 b. Cranborne, Dorset
Agnes Jackson 9 months b. Westminster, London
RG12; Piece: 81; Folio 12; Page 21
And likely in Carluke by 1901:
Bessie Jackson 34, reservist's wife b. Wiltshire
Agnes Jackson 10 b. London
John Jackson 9 b. London
Prudence Jackson 7 b. Lanarkshire
Ephriam Jackson 6 b. Carluke
Jas Jackson 3 b. Carluke
Walter Jackson 6months b. Carluke
Address: Roadmeetings, Carluke
You probably already have these census entries but it just helps in identifying the family

Have you ordered the 1890 marriage cert to confirm fathers' names for John and Bessie?
Monica