cooltungtung
Perhaps you can try make some fried ginger rice for her, let her eat for a few days. or give her some ginger candies during breakfast. See if this can help. Also, there is a kind of wrist band that can help to improve travel sickness. My son used to vomit in bus or vehicles with 4 wheels (not in MTR). The worst time was he vomited once he got onto the bus (the bus hasn't moved yet!) I bought him the wrist band, it seems work, at least he can stand for around 30 mins. You can find them in sport shops. I trained him a lot before school starts, sometimes he vomited sometimes he didn't. Now luckily he hasn't vomit in the school bus.
Also, perhaps you can stop giving her milk in the morning, strictly solid food for breakfast.
I have heard that last year there was also a girl vomited every day until November! The school then sent a note to her parents asking them not to give her any milk in the morning.