I thought this might be the case, and I was going to use my favourites Tanya and Zola at Colchester as an example, the I realised I'm not actually sure if they're related or not (I think they aren't). Anyway I don't they are particularly close anymore so maybe it is a bad example. That's quite interesting to know about all of those rescues that arrived together as other users have covered, it is a lot more clear to me now about the past of those elephants now, and Lucha and Kaylee seem unlikely to be related. I am also realising more and more now the importance of Donna's calf, not just genetically- it will/could be the first calf born at Whipsnade for 6 years (successfully), and the first elephant calf born in the UK for nearly 2 and half years- strange considering the last two were born within a month of each other, at Chester and Howletts just before lockdown. I now understand that a lot of the size of Whipsnade's herd was just made up of these rescue females, some that lived their whole lives at Whipsnade, others from London, and the lack of individuals now is from the rescues coming to the end of their lifespan. It is interesting to see though how successful Chester have been with Thi, compared to Whipsnade with Kaylee. Thi had a grandaughter in 2004 and a great grandson in 2012, while Kaylee only has another chance at a successful grandcalf in 2022.
I am sure now though, that Whipsnade will have a good chance at establishing a proper matriarchal herd now, similar to Chester's