Trish
I've got no answers to the puzzle over Robert, just adding a little more detail to what has already been posted.
The Robert that you have with mother Janet in 1891. This looks like the family entry in 1881:
Robert Russell 39, Coach Body Maker, b. Glasgow
Jessie Russell 36, b. Glasgow
Robert Russell 3 , b. Glasgow
Catherine M Russell 10 Months, b. Glasgow
Address: 14 Mathieson Rd , Kelvin Glasgow
You have the family in 1891. This looks like the family in 1901. Interesting to note young Robert's occupation:
Jessie Russell 57
Kate Russell 19
Robt Russell 27,
Railway Porter - not sure about Robert's age on this, maybe the original image would be clearer.
Address: 17 Brown St, Milton Glasgow
On Ancestry's WW1 records, there is an entry for a Robert W Bisset, age 18 and 1 month, a millworker from Troqueer (date of military discharge 1894, after only 3 days service). Mother Janet Bissett (next of kin), living at 131 High Street Dumfries.
This looks to be this Robert's 1891 census entry with family:
Janet Bisset 58, head, receiving parochial aid, b. Dumfries
Thomasina Bisset 20, b. Morton Dumfries
Robert Bisset 13, b. Maxwelltown, Kirkcudbrightshire
Josephina Bisset 2, b. Dumfries, daughter (unlikely
, maybe Thomasina's daughter?)
Janet Bisset 89, mother, receiving parochial aid, b. Priestland, Kirkcudbrightshire
Address: 131 High St, Dumfries
This looks like Thomasina's birth entry on IGI, born on 08 SEP 1870 Morton By Thornhill, Dumfries - mother Janet Bisset
Quite a puzzle you have here!
Monica