Mmmm....

I think that the 1901 Skinner family is close, but not the right one. But there is a Valentine connection but via another female Valentine.
Playing around with the free searches on the 1911 census, links up the following Skinners in one household in Montrose (the other group in Montrose for 1911 seems to be the family of Peter and Annie already mentioned):
James 50
Stevenson 16
William 15
Catherine 12
Robert 10
Alexander 7
George 5
Annie 2
Maybe connects with this entry for 1901:
James Skinner 37, Dock Labourer b. Dundee
William Skinner 4 b. Dundee
Catherine Skinner 1 b. Dundee
Mary Valentine 28, servant b. Dundee
Address: 8 Shore Wynd, Montrose
Monica
Added: Possible a late marriage? A James Skinner married a Mary Valentine in 1911 in Montrose....