Not normal but very common. Very hard to get a "perfect" iPad without light bleed.
Don't worry about it and you won't care eventually. When I got the iPad 2, I had the same kind of bleed near the home button. For a day or two, I obsessed over it and was considering returning it. But after that I stopped worrying about it and don't even know it's there, because I don't ever use my iPad at full brightness and that's the only way it becomes visible.