Hhmm trying to find a marriage for Kemp/Petty and not coming up with anything. However I seem to have found the marriage of Elizabeth's parents:-
George Kemp to Mary Ann Newman on 28 September 1834 at Minster in Sheppey, Kent. Groom's residence given as Teynham.
So the Teynham fits there.
This appears to be Elizabeth's birth registration:-
KEMP, ELIZABETH NEWMAN
GRO Reference: 1840 J Quarter in FAVERSHAM UNION Volume 05 Page 174
I've found Elizabeth's family in the 1841 census living at Blue House, Teynham, Faversham, Kent
Parents George and Mary and two older siblings Mary (1836) and George (1838).
Registration District Faversham
Piece number 476
Book number 4
Folio number 22
Page number 6
In 1851 living at Barrow Green, Teynham, Faversham, Kent, now has four younger siblings.
Registration district Faversham
Piece number 1626
Folio 566
Page 19
Well this is interesting. Elizabeth is still with her family in the 1861 and still single.
I'm not finding any marriage between a Petty and a Kemp up to 1874.