Over-invested here. I'm trying to work out when Sarah was born. If she lived to be 104, and we take the time of writing to be the present day, 2019, that makes her born in 1914. So in her 30s by the time she was liberated from Ravensbruck, pushing 40 when she came back to Australia, and early 40s when David was born. I thought she was supposed to be a bit younger than that. Or maybe 'now' is a bit later?
To be honest I preferred the early series when Sarah and Elizabeth were such fighters. Too much gazing into the middle distance in the later series. I loved the series when we got some of Elizabeth's back story, it made so much sense, and the actress who played young Elizabeth was so uncannily like her older self. But I kept watching and I'm sad it's ended, as presumably it now has.