Hi

Not sure but this may help, if you go back to the 1851 census there is only one Elizabeth Rudman who is in the right place, she is living at Water Lane Somerford Keynes her age is 17 and living with her parents father John and mother Hester. RICHENS,so a second marriage for her mother.

But there is no Elizabeth Milsom living in this place

In the 1861 census this Elizabeth Rudman is still at Water Lane Somerford Keynes living with her parents but she is now married called Elizabeth Parsons she has a son John W aged 3
Her parents John and Hester have been transcribed down as Richings everythig is the same as the 1851 just the surname Riching has been spelled diffrent

Shelagh