Yes I'm Jade's cousin. I know from Jade that James never came back from war and that her dad was registered in his name and not in his real dad's surname(Jones), from researching I found Peter's younger sisters were registered under both James Hoban's name and their father Walter Jones. Since Emily never remarried, the children were automatically registered in her husbands name.
I searched for James P Hoban from Leeds, in army records and found he died in 1940 on the Lancastria, so I assumed Mary and Coleen were probably not James Hoban's children either. His name was James Patrick Hoban. So I don't believe he is the same James Hoban from Aston, Birmingham as it looks like that James died in the 60's.
This is his death on roll of honour from findmypast
Name: James HOBAN
Memorial Scroll
Purchase scroll
Rank: Private
Initials: J P
Birthplace: Leeds
Residence: Leeds
Branch at death: Other Corps, Etc
Regiment, Corps etc.: Pioneer Corps
Branch at 01/09/39:
Regiment, Corps etc.:
Number: 13005931
Date died: 17 June 1940
Theatre of war: At sea
I found him on the Lancastria Victim list, it has a number near his name (37) which I'm guessing is his age. So I figure born in Leeds in 1903.