I’ve been along this path too. I was thinking that Isabella’s husband couldn’t have died in 1852 as Eliza was born in 1859, but then only her mother’s name is given in the baptism record, according to the IGI. The previous child, Fell, was baptised in June 1852 so would have been conceived before Dec 1852.

(1861) Glenchast, Rushen RG9/4430 f.64/65 p.10/11 sch.61
Isaballa Watterson H wid 37 Ag labourer Rushen
Elenor d 14 Ag labourer Rushen
Ann d 12 scholar Rushen
John s 10 scholar Rushen
William s 8 scholar Rushen
Fell s 7 scholar Rushen
Eliza d 2 Rushen

John Watterson & Isabella Collister married 9 Dec 1843 Kirk Rushen IGI ext

Ellen Watterson d/o John Watterson & Isabella Collister c.6 Oct 1844 Kirk Rushen IGI ext
Margaret Watterson d/o John Watterson & Isabella Collister c. 24 Jan 1847 Kirk Rushen IGI ext
Ann Watterson d/o John Watterson & Isabella Collister c.10 Sep 1848 Kirk Rushen IGI ext
John Watterson s/o John Watterson & Isabella Collister c.24 Feb 1850 Kirk Rushen IGI ext
William Watterson s/o John Watterson & Isabella Collister c.19 Oct 1851 Kirk Rushen IGI ext
Fell Watterson s/o John Watterson & Isabella Collister c.5 June 1853 Kirk Rushen IGI ext
Eliza Watterson d/o Isabella Watterson c.22 May 1859 Kirk Rushen IGI ext

(1871) Glenchast Road, Rushen RG10/5778 f.92 p.7 sch.38
Isaballa Watterson H wid 48 labourer Rushen
Lizea d unm 13 scholar Rushen

Richard Moore married Eliza Watterson 23 Dec 1880 K Rushen IGI ext

Richard was the son of Richard Moore and his 2nd wife Jane Connor, widow of the Thomas Witted who was also killed on the Brig Lily:

Richard s. of Richard Moore & Jane Witted PSM labourer, 20 Sept 1857 K Rushen:

(1871) 2 Flitter St, Port St Mary, Rushen RG10/5778 f.120/1 p.28/29 sch.144
Richard Moore h m 50 Ag lab Rushen
Jane Moore w m 41 Malew
Richard s 13 scholar Malew
William s 12 “ Malew
Thomas s 10 “ Malew
Eliza d 8 “ Malew
John Moore (p.29) s 6 Rushen
Samuel s 3 Rushen

(1881) “Amy” CT 32 RG11/5609 f.90 p.15 Fishermen at Kinsale
Fayle Watterson s 28 Fisherman b. Rushen res. Rushen
Richard Moore m 24 Fisherman b. Rushen res. Rushen

(1881) High St, Port St Mary RG11/5609 f.24 p.6 sch.32
Isabella Watterson h w 58 housewife Port St Mary
Eliza Moore d m 22 dressmaker Port St Mary

(1891) “Anna” Ct33, Rushen RG12/4692 f.76 p.6
Richard Moore H m 32 fisherman Rushen

(1891) 14 Lime St, Port St Mary RG12/4692 f.69 p.35 sch.170
Eliza Moore Wife m 31 Rushen
Richard s 10 scholar Rushen
William s 8 do. Rushen
Thomas s 5 Rushen
Henry s 2 Rushen
Isabella Watterson m-in-law 66 Rushen
(Moore indexed as Lawson on Ancestry)

Lawson Births
MOORE, Richard John, 15 Jun 1881, Rus, MOORE, Richard & WATTERSON, Eliza
MOORE, William Samuel, 23 Aug 1883, Rus MOORE, Richard & WATTERSON, Eliza
MOORE, Thomas Fell, 11 Jun 1886, Rus MOORE, Richard & WATTERSON, Eliza
MOORE, Henry James, 22 May 1889, Rus MOORE, Richard & WATTERSON, Eliza
MOORE, Isabella Jane, 6 May 1893, Rus MOORE, Richard & WATTERSON, Eliza
MOORE, Herbert Joseph, 13 Jun 1895, Rus MOORE, Richard & WATTERSON, Eliza
MOORE, Walter Arthur, 22 Jun 1898, Rus MOORE, Richard & WATTERSON, Eliza
MOORE, Eliza Anne, 29 Dec 1900, Rus MOORE, Richard & WATTERSON, Eliza

(1901) Loch Road, Port St Mary RG13/5301 f.76 p.22 sch.144
Richard Moore H m 43 Fisherman Port St Mary Eng. Lang
Eliza w m 42 PSM Eng “
Richard J. s 19 PSM Eng
William S. s 17 PSM Eng
Thomas F. s 14 PSM Eng
Isabella J. d 7 PSM Eng
Herbert J. s 5 PSM Eng
Walter A. s 3 PSM Eng
Eliza A. d 4mo PSM
Henry J. s 11 PSM Eng
Isabella Watterson m-in-law wid 80 PSM Both

Does any of that help?