Nothing is common for homeschooled children – since every homeschool family is different.
After all, that’s one of the great strengths of homeschooling.
Our family does not watch “TV” (in other words, we don’t have a cable or satellite subscription). We do have a Netflix subscription. Once or twice a week, we will select a movie or series to watch, but it’s not on a set schedule.
Our daughter has pretty open access to the internet (probably 2–4 hours per day). She has several email accounts; several YouTube channels; a number of game accounts (including her own Minecraft server), and an account on Wattpad (where she posts her writing). She has two screens, and she will often watch “goofy” videos (such as the crazy Russian guys) while she is doing other things.
She also practices violin, piano, and swimming daily, and reads 4–5 novels per week.
So, the answer is, she doesn’t watch TV all day.