Hi Debra,
Thanks for your input. Yes, I agree John Yates couldn't have been the father, but I'm pretty sure that Louisa Baker was the mother - (now-days however ....!). Thanks for the link to Bendigo Family history. I'll have a good look around there and contact them. With a total of 10 children and no 'husband', I wouldn't be surprised if Louisa didn't even baptise the children. I even wondered about them being the children of a brother or sister of John or Louisa - but that doesn't seem to add up when you work down that path. (There are some children with similar names born in Mt Prospect / Ballarat to Yates families, but from what I can see they are all accounted for elsewhere.)
Judy