"The grind of having to be on top of our games, the grind of keeping up with everything that we do: charity work, awards shows and of course, practice. And also trying to find a moment, like, to make sure we're with our family, which we do have a lot of moments."
Serena, 25, says the series is a "family project."
"It's not just myself and Venus," she said. "It turns out you get to learn a lot about my older sisters, like Isha and Lyndrea, and my mom and my dad. And you get to see the dynamic relationship that all of us have, so it's really cool."