Birth records are available online up to a ~100 year cutoff, currently up to 1921 on IrishGenealogy.
I checked for children of Christopher and Bridget and located the following :
Rose 19th April 1917, 4 Courtney Place, father's occ. labourer
John Patrick 4th March 1919, 43 Old Kilmainham, father's occ. labourer
Christopher 14th October 1920, 18 Poole St., father's occ. labourer
all Dublin city, place of birth same as residence for each
I also managed to locate a
possible marriage for Rose close to the cut-off for marriages in 1946 - father's occupation is gardener rather than labourer, but maybe the death cert you mentioned might help confirm that..:
Marriage of John O'Loughlin and Rose Kelly 6th August 1945 at St. Agnes RC Church Crumlin, Co. Dublin
fathers Daniel O'Loughlin and Christopher Kelly
