The marriage record for them in 1854 gives his father as John Taylor and her father as Richard McKenna. There are only five Richard McKennas in the Tithe Applotments in the 1820s -- all in Dublin. The addresses suggest that they may all be the same person (or perhaps two people):
Richard McKenna, Seatown West, StPatrick's, Dublin 1827
Richd McKenna, Magillstown, Swords, Dublin 1824
Richd McKenna, Magillstown, StPatrick's, Dublin 1824
Richd McKenna, Seatown West, Swords, Dublin 1828
Richd McKenna, Magillstown, Swords, Dublin 1828
Given that they were married in Liverpool, it does not necessarily follow that they knew each other in Ireland so the Taylors may come from somewhere else entirely.