When I was a teenager I was my parents natural go to for babysitting my little brother.
I wouldn’t say it was being taken for granted, but more it was being trusted, since psychologically speaking I could have resented suddenly becoming second in the queue for my parents. I am fortunate in that we are a close family and often if I had lots of homework my grandparents took over caring for my baby brother, and I was given the opportunity to study.
It worked because I have a language based degree from our local university. I’m still as close to everyone even though I am living in England.