It took mine about three – four weeks each.
its pure torture as a parent but they do settle & they love it & they make friends & learn so much.
But the first few weeks are very hard, so be prepared. Both times i said that i was giving up work as i couldnt cope with the upset in the morning but we got through it.
Plus be prepared for a narky little child in the evening as they do take their anger out on you for leaving them.
I think the sercet is to be really positive about creche, talk to her in the car about all the fun things she is going to do in the creche each day. Always say goodbye but make it quick & walk away, even if she is crying.
In my creche they let me watch them on the cameras from the office for a few mornings. The creche staff are so good at distracting them & within 10 minutes they had forgotten about me.
Good luck.