She is not too young. Many preschools around here have 2 year old classes (for the kids who are 2 as of Sept 1 - the school cut-off date).
Decide if you want a preschool or a daycare-type place (that sometimes call themselves preschools). A preschool more-or-less follows the public school schedule - summers off, christmas break, spring break, etc. There's a set schedule each day and everyone arrives and leaves at the same time, and the entire class moves 'up' at the same time -- when school starts in the fall. The children in the classroom are the same everyday there's class for the entire school year - which is great for developing and maintaining friendships.
The daycare type places are open all day so parents are dropping off/picking kids at random times throughout the day. Kids go year-round and usually switch classrooms on their birthdays instead of all at once. There isn't as much stability in the classroom because kids are coming and going at different times, and on different days.