(+)her first class does start at 9 o'clock. ☝ утверждение теперь как сделать вопросик? через when или does.

When does her first class start?

When - это вопросительное слово
Does - это вс глагол, указывающий на настоящее время

Они могут вполне употребляться вместе, как и в этом предложении

Topic 2: in our school there are children who lead a healthy diet. they eat everything, then they get fat, and when people are fat, it becomes difficult for them to live. and to avoid this, you need to eat healthy food that does not harm human health. and only strengthens the human body, makes it healthy and strong. there is such a problem in our school, it can be solved. in our school you need to prepare salads in the dining room, in which there will be tomatoes and cucumbers, because vegetables are good for humans, strengthens the body, there are vitamins.

topic 2:

in our school there are children who lead a healthy diet. they eat everything, then they get fat, and when people are fat, it becomes difficult for them to live. and to avoid this, you need to eat healthy food that does not harm human health. and only strengthens the human body, makes it healthy and strong. there is such a problem in our school, it can be solved. in our school you need to prepare salads in the dining room, in which there will be tomatoes and cucumbers, because vegetables are good for humans, strengthens the body, there are vitamins.