slight problem I think - the 1841c does indeed give age of Elizth with Hugh as 12 (and Hugh as 50 tho Hugh is I believe bur bur Malew 18461125 age 72 (which fits with bapt as Ewan Malew 17740626) - there is no bapt of a 12yr Eliz to him + wife Cath Bell but there was an Elizth bapt to them Malew 18230921 which fits the burial of an Elizth Malew 18520330 age 28.
There was another Elith Creetch of the correct age c/o robt + christian mills bapt Mal 18270204 (they are at Ronaldswey(malew dist 5 page 3) in 1841c but Elizth is not with them in 1851) she is the 24yr serv with james blyth - the other eliz creetch age 26 in 1851c is un-married and with her much older sister cath (age 42 which fits with bapt Mal 18120308 d/o hugh - widowed ? ?marriage however but son John for whom I can't see an obv bapt) at 43 Malew St