1911 census Household transcript from Findmypast [corrected]:

FARGHER, Paul Head Married M 44 1867 Farm Labourer General Isle of Man Santon
FARGHER, Emma Wife Married 23 years F 46 1865 Isle of Man Rushen
FARGHER, Frederick Son M 15 1896 Isle of Man Braddan
FARGHER, John Son M 12 1899 School Isle of Man Patrick
FARGHER, Benny Son M 11 1900 School Isle of Man Malew
FARGHER, Amy Daughter F 9 1902 School Isle of Man Malew
FARGHER, Harry Son M 7 1904 School Isle of Man Onchan

RG number: RG14
Piece: 34641
Reference: RG14PN34641 RD635 SD1 ED4/2 SN59
Registration District: Isle of Man
Enumeration District: 4/2
Parish: Braddan
Address: Speke Braddan Isle of Man.

The scan shows that Emma had 5 children born alive, 5 children still living.
The form was filled in by Paul, and there is always the possibility that he thought the form referred only to the children recorded there (having been married for 23 years).

Sue