No questions are silly. Most breeds start laying at approximately 20 weeks. Large breeds like Brahma a tad later.
Most people just cull an internal layer as it can be an ongoing issue and is tough on the hen. Personally with mine, I check her abdomen each day for swelling. If I feel a tiny bit at all I watch her till she poops, if she poops yellow or liquidy poop (or if I see a mess below her vent that indicates that has been going on) or if I decide to give it one more day to see if swelling gets more pronounced....if so... I start her on a broad spectrum antibiotic found in the cattle section of the feed store that is also geared for poultry. I mix a little up each day and force feed it to her (humanely, her and I have an understanding, I am able to hook a tiny cup under her top beak and spill a splash into her beak over and over for just a safe drink many times over) and I soak or float things in the antibiotic water like meal worms and boiled egg so that she gets a bit more as she eats. The first time I just isolated her and it was her only water source since she was sick as sick could be without dying but now I catch it early and think her appetite stays better if I leave her with the flock and she eats with the competition. I get as much antibiotic water down her as I can in 10 days. The 2 subsequent times it has happened after the first went well. her appetite goes down due to the antibiotic so I still try to entice her to eat when I am medicating her with extra treats like chick food soaked in antibiotic water, blueberries as well. Usually her abdomen continues to swell and she gets more sedate and lethargic for a couple more days until the antibiotic starts to do its job (as well as her own immune system being able to help because I catch it when she is still pretty healthy) then about the 4th and 5th day she is pretty swollen still but not getting any worse and then usually by the 6th day her tummy starts to go down, and by the 8th day she is fighting me to not take any more of the water but we persist for the full 10. Then she goes for a few more days with a decreased appetite because the antibiotic is tough on her tummy but I feed her yogurt to help restore the good bacteria to her stomach and usually about 3 days later she is eating like a champ and packing on weight again. I am hoping she will just soon be out of eggs to try to lay and will live out her days healthy again. Her flockmate that is the exact same age and breed lays an egg about every 10 weeks or so, usually not a strong shell and it breaks right away so whatever it is that is wrong is probably a problem with the breed from this hatchery but that few of eggs tells me they will hopefully just be done laying soon. An occasional internal lay may go unnoticed as many times it is just absorbed into their system with no issue but if they build up that is when the problem can happen. My chickens are pets mostly meant to fertilize my garden and give eggs secondarily so they live till they die naturally or are in too much pain to be humanely kept alive. If this was something that happened continuously I may have a different approach with her but since the majority of her time is spent as a happy chicken and a small percentage is spent being what I perceive as simply an upset tummy with maybe some tenderness I just monitor and treat her.