S.D.
Honestly the two year old will prob not get a lot out of it aside from being excited running from one place to the other with the kids. depending on the amount of the kids..... I would break them into teams. a younger with older and give them all a job. One holds the bag, one holds the egg and one reads off the clue. The egg is a great idea. You hide the princess and then lead them back wards as your setting up. So if you put the princess in the closet, you put a clue as to wear you would place your shoes. Then that note goes in a fridge and in the next note is leading them to the fridge and that note is placed in the tree and so on and so forth. But I suggest you start backwards. the eggs can contain the clue and then a picture so both kids can get what they are saying.
you can also draw a huge map and pictures to lead them to the eggs and then the two year olds can find the egg but the older ones can do the whole treasure map. The treasure is the princess and you can be really detailed in the pics on your map.
Sounds like so much fun !