According to GENUKI the baptisms of Crathorne go way back but the earliest MILBURN I have found is 1830. The baptism images on FindMyPast show some PROUD baptisms but not quite back to when Elizabeth was born and it does not show the Catherine who was witness at the wedding.
Baptisms in Crathorne on FindMyPast for surnames PROUD and MILBURN.
First entry -
29 January 1813 Eliza daur of Richard & Jane HUMBLE of Crathorne, Farmer.
21 June 1813 Hannah daur of James and Margaret PROUD of Crathorne, Blacksmith
26 November 1815 Catherine daur of James and Margaret PROUD of Crathorne, Blacksmith
22 June 1817 Christopher son of James & Margaret PROUD of Crathorne, Blacksmith
first MILBURN entry -
17 January 1830 Mary (born 15 Jan’y) daur of John and Ann MILBURN of Crathorne, Hind.
21 May 1832 Jane (born 19th May) Jane daur of John & Ann MILBURN of Crathorne, Hind.
2 Jan’y 1836 Henry (born Dec 29) son of John & Ann MILBURN of Crathorne, Hind.
Stopped looking after 1845