Patrick's mother hasn't been recorded either by the looks of it. The rest of the entries on the page are full, strange.
possibly an orphan and would'nt know who her parents were
Looks a decent possibility. In the 1901 census, it says that Elizabeth cannot read or write, whereas, her husband and all her children can. I know this wasn't uncommon at that time period. But, could be another indicator of a rough childhood?