Struggles Of Parenthood
You can imagine the struggles of being a parent while also being the next King of England. This makes it more difficult to raise your kids in a more normal way, with the couple obviously having many nannies to help them out.
Although they clearly have access to these nannies, its not like the royal couple don’t want to be involved in raising their children. The Duchess claims that there are indeed struggles in raising the kids, but not anything out of the ordinary. Although the struggle is different coming from the royal family, it still resembles that of a normal parenthood.