Do you do your exercises every day? Yes i do Do you make your bed every morning? Yes i do Do you tidy your room? yes i do Does your dad wash the dishes? yes he does Does your mum walk your pet? No she doesnt Does your friend feed his pet? Yes he does Does your friends help their mums yes they do Подскажите пожалуйста правильно ли моя дочь вставила Do или Does? И ответила на вопрос? Я сама не могу проверить? так как учила другой язык.

Все ОК, кроме 
Does your friends help their mums yes they do
ответ правильный, а вопрос надо так DO your friends help their mums?