Wendt

Hi
My name is nerys Welch and I am researching my husbands family tree.
His mother was Ruth Laura Wendt born 6th October 1931 in Detmold, Germany. Her father was Franz wendt born in 1899 in Detmold. Her mother was called Elisabeth. I believe Franz wendt had 2 families at the same time but am not clear on the details.
I don't know much as Ruth died about 18 years ago. She did move to England in the 1950's and married a Balston. Then she married my husbands father Reg Welch and they moved to Australia.
Ruth came from a large family, around 11 siblings. One went to Wales but I believe the rest stayed in Germany.
The family aren't sure on whether they stayed in Detmold or moved to Berlin. Also some of the family was from Hungary but am not sure who.
I would appreciate any help or information you could give me on how to trace this family.
Thanks in advance
Nerys Welch