Walter Roberts & Frances Maynard DID have a son John Roberts, but he was baptised at St Dunstan, Cranbrook, Kent, as were their other children. His baptism was 14th October 1571. He is said to have died in April 1582.
No child of theirs was baptised in Rye, East Sussex, and certainly not in 1586, SIX years after Walter Roberts had died and six years after Francis Maynard had married again.
What evidence is there for attaching an American John Roberts to the tree of the Glassenbury, Kent Roberts?