Why not, 'Avez-vous une grande sœur?
It's also a correct translation.
Surely you're far more likely to say 'vous' rather thn 'tu' when asking a question like this unless speaking perhaps to a young child
This isn’t a question about this translation, but my iPad keyboard shrunk and moved to the left of my iPad. I can’t get it back to normal. I’m not sure what caused it to move. On peut m’aider?
Hey, do you still need help with this? There might be a little button on the keyboard with four arrows pointing away from each other - try that
Thanks. It was resolved.