My Red Star Isabel is 61/2 months old. She began laying at 5 months. About 4 weeks ago she was out in the yard when I noticed she was not pecking and scratching like her sisters. She was just standing in one place. I'm a new chicken owner', but despite that, I think I figured out that she may have had an impacted crop. It felt like a hard small golf ball. I gave her a little cooked, plain oatmeal with olive oil and she was fine the next day. Today, while out in the yard with her sisters, she began behaving the same way: standing still and not pecking or scratching. I picked her up and brought her into the confines of the run and examined her. Her crop felt soft and squishy and normal sized. I did not detect any bad breath. She laid a normal sized egg this morning, but I felt under her to see if there was an egg stuck. Everything felt normal. No one is pecking at her. Tonight, when we checked on the girls (we have 5) around 11pm, all we're roosting up on the perch, except Isabel. She was on the coop floor in a standing position. Here is some other info: she eats layer feed and is offered oyster shells in a separate bowl. She has been known to lay some large eggs, usually double yolks, the most recent of which was yesterday. She is our smallest chicken. She is normally very lively. Today, I changed their water in their large water feeders and added a bit of ACV. They also got oatmeal this morning (cooked in water, nothing added), which is an occasional treat for them. Her poops are normal to sometimes runny. Today during the weird behavior, we noticed a clear, almost mucus-like substance, come from her vent. Not very much, but enough to make us wonder what is going on. Eyes are fairly normal, but may be very slightly watery. Comb looks normal. We use pine shavings in the coop, and straw in the nesting boxes. Her egg today was normal. We love our girls, but we won't be doing any heroics with a vet. Any help on what may be wrong with her and how we can help her is greatly appreciated. Thanks much.