It's better to switch them to layer feed a few weeks before you get an egg but since most people don't know exactly when to expect an egg, they don't switch until they see an egg.
Switch them to layer feed now because they need the calcium.
She might have something respiratory going on.
The last stress the better. If a vet is an option, take her. If not just watch her from a distance.
Stop the daily treats immediately. Mealworms are high in fat.
Scratch for that matter is too and if they eat more than one tiny spoonful of treats per day then they're overfed treats which causes them to pack on fat on their organs. They become fat on the insides. That fat can cause them to have trouble breathing and laying and all kinds of other issues.
It's preventable by what you feed. Feeding treats takes away from the bird getting a balanced diet which causes issues too if they're not getting enough of the proper nutrition.