We lived in Ecuador for a few years and it's typical to start pre K at 3. Then when we moved back to the US they had to hold us back until we were the same age as the other kids. But my mom never regretted it because we were always ahead of the class! I say go for it!

If financially able I would put my kid in school at 2-2 1/2 for a couple short half days so they can learn different things like listening to others and playing with friends...

I don't put my son in anything because he was in daycare till he was 3 1/2, I spent the time with him running a daycare. He started kindergarten when he was 5. His birthday is August 31st, he started school end of September because of the teacher strike, this year he's just turned 6 today and he starts school on September 8th.

My daughter started in toddler 2's twice a week, 2 hours, bridge to pre-k at 2 1/2 three days a week 2 hours, 3 year old pre-k 5 days a week for MW 4 hours but with extra phonics for 1.5 hours, TUESTHUR 3.25 hours but with sports or tae kwon do after school, Friday 2.5 hours.  Now she's 4 turning 5 in January - I have her in pre-K Montessori 5 days a week for 7 hours (do naps or rest time if needed).  Get her ready for full day kindergarten next year at the public elementary school.   I did full day because I'm due any day now and she will get more attention and will at least do more at school than sitting at home with me dead tired from a newborn either watching TV or playing on an iPad ....

My kids went to k3 at headstart when they were 3 and then at the age of 4 the went to Pre-k at the same headstart just a different room. If you decided not to send her you can always look up free websites for Pre-k age or use abcmouse.com it is like $8 a month but totally worth it. Then she is still getting some Pre-k just not in a classroom setting.

We did pre K at 4 but there were kids as young as two in pre k depending on how advanced there development was. I think it just depends on your child and what she is ready for :)

My daughter done headstart at 3 and prek at 4. I'm sure different states have different rules but idk. 

Kindergarten is 5. 

My daughter is in 3 k and loves it. She gets to play with lots of kids her age and has grown so much since starting.

My kids will be doing preschool starting at 3. :) You can wait if you want, but starting now wouldn't hurt either.