Just to fill it out:

Charles Watterson married Isabella Fell 15 May 1858 Kirk Rushen IGI ext
?Margaret Jane d/o Charles Watterson & Isabella Cregeen c. 5 Nov 1860 Kirk Rushen IGI ext
?Eleanor d/o Charles Watterson & Isabella Cregeen c. 15 Mar 1863 Kirk Rushen IGI ext

(1891) 5 Shore Rd, Pt St Mary RG12/4692 f.67 p.21 sch.140
Charles Watterson h m 54 Fisherman Rushen
Isabella w m 62 Rushen
Annie Kelly d m 40 Rushen
Eleanor ?Craige gdaur 3 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 )

At No.3 Shore Rd, Port St Mary, there is another Watterson/Cregeen family, but I'm not sure of the significance of that:
RG12/4692 f.67 p.21 sch.138
Margaret Watterson h w 73 Rushen
Margaret Cregeen d w 43 Rushen
Thomas H Cregeen gson s 20 Railway porter PSM
William A Cregeen gson 6 scholar PSM