if my friend gets late in waking up in morning, then she prays in the car when we pick her up. she prays for 5-7 minutes while counting on her fingers and has her eyes closed.

how are we supposed to behave when she is praying? do we have to keep quiet or can we talk? she never shushes us when we talk but it feels very odd when she prays in front of us. She gets late veryoften so most days she prays in the car on the way to college./