Yes...it sounds like she is too hot. Chicks will peep in distress if they are too cold, too hot, too hungry, thirsty, etc.
Place the heat lamp at one end of the brooder so that the chicks can go under it when they are cold but have room to wander around if they get too warm. Each chick will find its happy spot.
Never place the water and food underneath the heated area. It makes it hard to eat if the chick is too warm already, creates hot food and water, and allows bacteria to grow rapidly.
Watch your babies. Happy chicks will sleep, poo, run around, have constant happy little chirps. Distressed chicks will be huddled in a ball together (cold), or stretched as far away as they can from the heat source (hot), and be cheeping loudly in distress.
LofMc