Mary Moriarty and father Daniel, a hatter

My great great grandfather Daniel Moriarty was living in Cardiff in 1861 with son Lawrence aged 18, a mariner, daughter Mary born in Ireland in about 1832 and her husband and family, Thomas Morgan. Daniel was a hatter. I've also found the marriage of a different Mary Moriarty in Cardiff in 1852 to William Murphy. Her father was Henry Moriarty, also a hatter. I find no trace of him in Cardiff. It's a big assumption but I wonder if Daniel and Henry were brothers. The only hint I can get from trade directories is that there was a milliner, draper and haberdasher in Bandon, Cork, in the 1860s called James Moriarty. Obviously that's just a wild guess. My great grandmother Mary stayed in Cardiff all her life but Daniel and Lawrence disappear after 1861. I can't even find a death for Daniel, born about 1799, so I'm wondering if Daniel went back to Ireland. It's so frustrating to hit this brick wall. Any help would be greatly appreciated.