Dorothy was registered as Jones but her mother's name was given as Clayton so she could be an illegitimate daughter of Gertie. Gertie had 4 sons and her husband was killed in WW1. The family think Dorothy was the daughter of Dorothy Kate Clayton, her sister, and Douglas Lowe who were married in 1915 but living apart by 1920. I don't have the birth certificate as this is just initial branching out from my original Lowe family search because I picked up this first marriage of my grandfather and a link came up to Dorothy's grandson which now seems to have closed!