We have four Barred Rocks and two Marans. They just started laying today at 6 months old. One of my Marans has laid two eggs within 10 minutes of each other. The first one cracked and the other was a bit misshapened. Both eggs had hard shells and seemed to be healthy...minus the shape. Is it normal for a chicken to lay two eggs within such a short time span? I thought it took 24hrs for an egg to form and be delivered. She is completely healthy and never had any issues with her or my other girls. Any thoughts? We feed our girls LayerPlus from Tractor Supply and even though it says we don't need to, we add crushed oyster shell to their grit and scratch. We've been feeding them this for the past two months, so they would have all the calcium they needed when they start laying...which is today, lol. Just worried. Thanks.