First time letting a broody hen brood *Question*

[Chickenrandomness]

So my Langshan went broody last week, and just a couple days ago my Blue Polish started laying.
I haven't stored the eggs or anything, just put the eggs under my Langshan when my Polish layed them.
I have three eggs under her now, and I'm thinking about stopping there as not to create a large hatching gap.

But my question is, will the chicks hatch at different times? Two were put under her on the same day, and the third about about a day and a half after.

Thanks in advance!