I haven't had a searchable tree on Ancestry for years so I don't think that it would have come up on your hints.
However, most of the information out there relating to Edward and Isabella prior to their move to Liverpool ( between 1865 and 1871) came from my own research that I passed to another researcher a good few years ago and who is my DNA match.
Isabella had a 2nd daughter who must have been born between 1842 and 1846.
I can't locate an original baptism but, she too had an RC baptism which is also annotated as convert.
Oddly, she was baptised 2 yrs before her older sister. My guess is that she was between 6 & 9yrs old at this time.
I also assume that this girl died in childhood because Edward and Isabella went on to have another child with the same given name
I would advise that you search the Irish Catholic Baptisms for St Columbs, Longtower as the sponsors for Edward and Isabella's children reveal a lot.
Isabella's eldest daughter was actually sponsor to one of the younger children and I'm pretty certain that my direct ancestor ( Edward's older brother) was the sponsor for a few of the others