Hi Mavis, The Registration of Birth /Genealogical Registration of Birth - would be the most accepted proof of birth I believe.
Registration of Marriage would show names of both sets of parents.including maiden name of the mothers. but the birth reg is best
Baptism might be considered as well?
My husbands family were from Kent England Faversham,Ashford,Bessels Green,Hythe. In England from William STANGER b 1632 Northamptonshire.
Cheers, Stella