I watched this more than 10 years ago so I don’t remember much and I can be incorrect about the following details.
It’s set in 17xx-18xx. At least 2 children(a girl and boy – I guess siblings) travel from the UK to colonial Australia to their parent. Once they arrive they get into a lot of adventures. I don’t even remember the details – maybe they look for treasure or to find their lost parent.
I guess it’s 2000s tv series and it’s more like a family/children tv series.