Believe I have found the family but I'm afraid there is no connection to Anstey that I can see at all and William Edward wasn't born in Staffordshire!
Frederick Knight and Elizabeth Arnold appear to have married in the June quarter of 1880 at Wisbech, Cambridgeshire.
In 1881 18 year old Elizabeth Knight, married, living with a Samuel and Emma Lee as a visitor - ref. RG11 - 3119 - 74 -20. Think Emma was Elizabeth's sister. She is shown as bc.1863 Blaby, Leicestershire. Frederick Knight - shown as married and living by himself at 7 Russell Street, Wisbech - is a Plumber, Glazier and Painter aged 30 i.e. bc.1851 at Huntingdon, Hunts.
1891 - ref. RG12 - 1219 - 5 - 4 - at Middleton, Northampton
Elizabeth Knight 26 (lost a couple of years) shown as the wife of a Journeyman Painter b.Blaby, Leicestershire
Arnold Knight 9 b. Wisbech, Cambridgeshire
Leonard F. Knight 7 ditto
William E. Knight 2 b. Middleton, Northamptonshire
Cannot find Frederick in 1891.
In 1901 - ref. RG13 - 2951 -118 - 5 - is a lodger in Dunton Bassett, Leics. but it states he is single!
I cannot find Elizabeth and the 3 children above plus any others that might have been born after.
1871 - Dingley, Northamptonshire - ref. RG10 - 3224 - 58 - 1
James Arnold 42 Gardener Domestic Servt. b. Brutenthorpe (?), Leics.
Sarah Arnold 42 b. Wanlip, Leics.
Emma Arnold 17 b. Bitteswell, Leics.
Sarah Arnold 12 ditto
Harry Arnold 9 ditto
Elizabeth Arnold 8 b. Blaby, Leics.
1861 Huntingdon, Huntingdonshire - ref. RG9 - 975 - 25 - 12
William Knight 43 Ironmongers Porter b. Papworth St. Everard, Cambs.
Ann Knight 45 b. Huntingdon
Edward Knight 12 ditto
Ellen Knight 11 ditto
Frederick Knight 10 ditto
Emma Knight 8 ditto
Charles Knight 7 ditto
Julia Knight 5 ditto
William Knight 1 ditto
Louisa Knight under 2 mos. ditto
So, from ca.1818 to 1891 there is no connection at all to Anstey, nor to Staffordshire albeit where they may have ended up.
Where were Elizabeth and her boys in 1901??
Annette