As a rule, if a second egg is still in the oviduct after the first one comes out, the poop won't be normal. But it's possible. So give the calcium to be safe. It won't hurt her. For excess calcium to harm a hen, she has to be getting it longer than for just a few days or even longer than one week.
So, it's a good idea to give her a calcium tablet once a day for a week so you can be sure she's back to one egg per cycle.
So, it's a good idea to give her a calcium tablet once a day for a week so you can be sure she's back to one egg per cycle.