Steve, I’ve copied some records from Ancestry and familysearch for you.

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Robert Morrison
Isle of Man Parish Registers
Other information in the record of Robert Morrison
from Isle of Man Parish Registers
Name Robert Morrison
Event Type Marriage
Event Date 09 Oct 1858
Event Place Andreas, Isle of Man
Gender Male
Marital Status Single
Father's Name John Morrison
Spouse's Name Margaret Christian
Spouse's Gender Female
Spouse's Marital Status Single
Spouse's Father's Name Robert Christian

Robt and Mgt both of Andreas, both signed.
2 of the witnesses were Thomas Christian and Catherine Christian
Mgt’s father Robert Christian, farmer.

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1851
Ballakelly, Andreas
Name Age
Robert Christian 48
Elizabeth Christian 49
William Christian 18
Thomas Christian 15
Magaret Christian 12
Catherine Christian 10
John Christian 5
Robert Radcliffe 54
Robert Bannan 12

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1841
Ballakelly, Andreas

Name Age
Robert Christian 35
Elizabeth Christian 35
Robert Christian 12
William Christian 3
Thomas Christian 6
Margaret Christian 4
Catharine Christian 1
Robert Radcliffe 45
John Cottier 15
Christian Caley 20

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Marriage of Mgt Christian’s parents:

Elizabeth Skinner
Isle of Man Parish Registers
Other information in the record of Elizabeth Skinner
from Isle of Man Parish Registers
Name Robert Christian
Event Type Marriage
Event Date 25 Feb 1826
Event Place Andreas, Isle of Man
Gender Male
Spouse's Name Elizabeth Skinner
Spouse's Gender Female

Image shows Robert signed, Elizabeth made an x-mark. Both of Andreas.
Witnesses James Skinner and Thomas Cowle.

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Robert and Elizabeth had several children baptised in Andreas but there’s no Margaret.

I’ve looked at lots of pages in the Andreas register and this one seems to be the only one which fits (but with mother’s name written as Catherine instead of Elizabeth---possibly a mistake on the part of the vicar):
Margaret Christian
Isle of Man Parish Registers
Other information in the record of Margaret Christian
from Isle of Man Parish Registers
Event Type Christening
Event Date 28 May 1837
Event Place Andreas, Isle of Man
Gender Female
Father's Name Robert Christian
Mother's Name Catharine Skinner

This 1837 date fits with the “age 4” in the 1841 census.

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Margaret’s husband died young:
Robert Morrison
Isle of Man Parish Registers
Other information in the record of Robert Morrison
from Isle of Man Parish Registers
Name Robert Morrison
Event Type Burial
Event Date 14 Aug 1866
Event Place Andreas, Isle of Man
Age 34
Birth Year (Estimated) 1832

Image shows residence Ballacottier (where Robert and Mgt Morrison were in the 1861 census).

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Margaret remarried:

Margaret Morrison
Isle of Man Parish Registers
Other information in the record of Margaret Morrison
from Isle of Man Parish Registers
Name John Cowley
Event Type Marriage
Event Date 31 May 1884
Event Place Maughold, Isle of Man
Gender Male
Marital Status Single
Father's Name Robert Cowley
Spouse's Name Margaret Morrison
Spouse's Gender Female
Spouse's Marital Status Widowed
Spouse's Father's Name Robert Christian

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Jean C