Details of Gillian's birth are not known.

Gillian married Gareth J. Bywater in 1963 in Birmingham, Warwickshire.

She had the following children from her marriage to Gareth J. Bywater:

- Steven J. Bywater	born in 1965 at Birmingham, Warwickshire.
- Sarah Jane Bywater	born in 1967 at Birmingham, Warwickshire.
- Richard Oliver J. Bywater	born in 1979 at Birmingham, Warwickshire.