How old do you have to be to play

Yes both are correct, but it is under construction right now. Open in November.

One section for 3 and under and one section for big kids

Crawling to age 10 I'd say

7 month can play in little kid?

They are under construction right now, but before there was a little kids area for kids up to 3 I think. Then there was the normal play area and they let parents play with their kids (they even have knee pads you can use)

I've seen 1-2 yr olds play in little kid area, and even I've played with my 6 yr old in the big area

Yes. Two sperate sections. One for the bigger kids and one for the little ones.

There is a separate section for the very little kids.