John K. Munsie's mother was NOT Rosalinda Croom even thogh the 1851 census seems to indicate it. John K; Wm W, and Mary K were born before William & Rosalinda's marriege.
From my CROOM(E) database, but not related to me:
Rosalinda Croom & William Munsie were married 15 June 1847
"On the 15th instant, by the Rev. William Arnot, William Munsie, Esq., to Rosalinda, daughter of the late William Croom, Esq". -- from Glasgow Herald (Glasgow, Scotland), Friday, June 18, 1847; Issue 4631
From 1851 Census
[Parish Number: 622, ED: 46, Page: 29, Household # 88, Line: 7, Roll: CSSCT1851_144]
William Munsie, age 49 [b. 1802], Head, English Teacher, born: Glasgow, Lanarkshire
Rosalinda Croom, age 40 [b. 1811], Wife, [no occup.], born: Glasgow, Lanarkshire
Ann C Munsie, 1 , Daughter, -, born: Glasgow, Lanarkshire
Robert G Munsie, 2 mo , Son, -, born: Glasgow, Lanarkshire
3 children born before William's marriage to Rosalinda, therefore from a 1st marriage (c. 1823): John K Munsie, age 17; Wm W Munsie, age 16; Mary K Munsie, age 12.
Sorry to cut off a root (or is it a branch) of your tree.