Hiding the eggs for the other kids to hunt might be fun for her. As I kid, my cousins and I would always rehide our Easter eggs for each other to find after the big family egg hunt. So if you want her to still be able to enjoy the family egg hunt without participating in the actual hunting, then have her help you rehide the eggs. But if you want her punishment to be being totally excluded from the family event, then I would just have her sit out while the other children hunt.
But after re-reading what I just wrote, total exclusion seems kind of harsh to me. I would hate one of my kids to miss out completely on a once a year event, even if she did almost ruin the fun for everyone. I guess to me it would depend more on her age and what you think her actual motivation was for doing it. If she's just young and excited and impulsive, to me that's different than if she understood that she was ruining the fun for everything else and did it anyway.