Bertha is still alive in 1939, a patient in the County Mental Hospital, Winwick, Warrington. Ancestry have indexed her dob as 20 Mar 1868, but it's actually 1887, looking at the image (the second 8 is very squashed)
Earlier someone said "If Bertha was of sound mind at that time - he could/would not have taken the children" I don't see why not.. When my grandparents split around 20 years later than this, my mother said it was considered very unusual that she lived with her mother, not her father
Thank you so much for the info, hopefully this is the right Bertha, although I seem fairly sure it is. Just ordered some certificates online to find out if there is anything that proves this is her
