I did find Catherine on the 1911 census living in Coed Madog Ucha, Talysarn with her husband John Hugh Williams and two young children, Hugh and Mary. Taking into consideration Mabel's findings that she attended her twin brother's wedding in February 1917 when she lived in Cae Mawr, Talysarn she was obviously more than 18 when she died. Would you believe we have actually stayed at Cae Mawr which is a lovely b&b now.
If someone has time I wonder if you could find her death as Catherine Williams of Cae Mawr please?
Thanks so much
Eleri