Hi have found them in the 1891 census in cardiff schedule no 437 at 23 bromfield st

John Rodgers
Margaret
Annie
Alexander J
Walter L
Albert Jas
and Mother Isabella (widow)

John is down as born in St Turnells, Pembrokeshire, Wales born about 1846

in the 1881 census

margeret
annie
john a
where with James and isabella in the isle of man