Egg at night

Hi all, my first post. Bought 3 chickens a couple of weeks ago 2 Rhode Island reds and a Hybrid.

All have now began to lay. But one of the Rhode island reds seemed to lay last night. I wasn't expecting this. When i opened the coop this morning there was yolk on the floor with a rubbery (Shell!!!) next to it.

Is this normal, one of those things, something to with her only just starting laying?

Thats what I hoped. thank you.