Census and Death Record - Analysis and Correlation of both Records

I have been trying to formulate a "discussion" in the Research Notes of one of my ancestor's profiles @ Wikitree. This is the base of it.

Unfortunately, a number of the 1841 Scotland census records are missing or did not survive, and Ceres is one of those. This is most unfortunate, as Ceres was most likely the parish where Isabell was living that year. No other 1841 census record that fits her profile has been located.

When she died in 1858, her son-in-law David Wilson registered the death. She was recorded under her maiden name of Watson, with no reference to being the widow of Alexander Swinton. Her father's name was recorded as Alexander Watson and her mother's maiden name was Malcolm (no forename given). It appears to me that David Wilson did a total botch up as the informant of her death. 

The reasons for this conclusion are:

1. She was living in his (David Wilson's) household in 1851 and was enumerated in the census as "Isabella Swinton, mother and a Widow". It's extremely doubtful that David Wilson gave the household information to the enumerator, as he was probably out working at the time and the relationship to the head of the house was recorded as mother. His wife Elspeth was more than likely the person who provided that information. 

2. In the same 1851 census, in the next household enumerated (schedule no. 38), there were three woman - Elspeth Watson (Head), Isabella Swinton (Niece) and Isabella Swinton (Nieces Niece). 

A recap of the residents of each household and an explanation of their relationships are:

Household 37:
1. David Wilson, Head, married, male, age 36, Turnpike Road Lab, born Ceres, Fife.
2. Elspeth Wilson, Wife, married, female, age 33, Weaver (linen), born Ceres, Fife.
3. Anne Wilson, Daughter, female, age 1, born Ceres, Fife.
4. David Wilson, Son, male, age 7, Scholar, born Ceres, Fife.
5. Alexander Wilson, Son, male, age 3, born Ceres, Fife.
6. Isabella Swinton, Mother [in-law], widow, age 81, born Kemback, Fife.

Household: 38
1. Elspeth Watson, Head, unmarried, female, age 70, Outdoor Lab, born Kemback, Fife.
2. Isabella Swinton, Niece, unmarried, female, age 36, Cook, born Cameron, Fife.
3. Isabella Swinton, Nieces Niece, unmarried, female, age 22, Weaver, born Kettle, Fife.

An analysis of the folks in this census in conjunction with available BMD records is: 

Household 37:
2. Elspeth Wilson, Wife, age 33 - was the daughter of:
6. Isabella Swinton, Mother, age 81 - who was the Mother [in-law] of:
1. David Wilson, Head 

Household 38:
1. Elspeth Watson, Head, age 70 - was the daughter of David Watson and Elspet Band and therefore the sister of: 
6. Isabella Swinton, age 81 in household 37. 
2. Isabella Swinton, Niece, age 36 - was the daughter of: 
6. Isabella Swinton, age 81 in household 37. 
3. Isabella Swinton, Nieces Niece, age 22 - was the daughter of David Swinton, who was the brother of:
2. Isabella Swinton, Niece, age 36 and son of:
6. Isabella Swinton, age 81 in household 37.

When David Wilson registered the death of his wife in 1873, her father was recorded as Alexander Swinton and her mother as Isabella Swinton M.S. Watson (both deceased). He obviously got that one right :-).

There is one conflict that needs attention, and it relates to her daughter Elspet Swinton who married David Wilson. No record of Elpet's birth has not been located. She was born c.a. 1818 (calculated from her age at death in 1873). Her mother Isabella (Watson) Swinton would have been age 48 at the time of her birth and it was 5 years after the birth of her last child. This would ''appear '' to have been after her mother's child-bearing age, although Elspet could have been a ''change of life baby.'' All her siblings births were recorded.

So does anyone have feedback for me? Have I explained/presented the information I have at hand in the clearest context?