M.S.
Did you mean to say she'd be in school 6 hours 6 days a week?
That aside, we are AP. My daughter wasn't ready before 3.5 for preschool (her school is all day, 9-3ish (you can drop off earlier/pick up later - whatever works for you). I left her for half a day for the first few weeks and she went two days a week. Eventually she wanted to stay, she did great but I won't lie, it was hard for her to part with me - I spent a lot of time at that school. She is in kindergarten now (at the same school) goes 5 days a week from 8:30 - 3:30 (I pick her up later often because she doesn't want to leave). My 3.5 yo son goes to preschool there and he on the other hand was ready long before turning 3 - but for me, younger than 3 is just too young (just my opinion). Actually, I always thought younger than 4 was too young, until I found this place. He goes 3 days a week, same hours as his sister and he just loves it. On the days he doesn't go, he is disappointed. I know he could do 5 days a week, but he doesn't need it, besides, I'd miss him more than I already do!
That was a long about way of simply saying - it is up to the child - they are all so different. Some thrive from the get go (my son) for other's it is torture (my daughter) both raised the same way.
Congrats on your pregnancy!
M.