How do you help someone with morning sickness

How severe is morning sickness supposed to be? I know that there’s morning sickness and then there’s like that horrible disorder you can get that makes you violently ill and my roommate is like in between that.

All I have is promethozine but she’s too cautious and doesn’t know if you can take it while pregnant and won’t rely on google and is waiting on her OB appointment to ask.

But she is barfing her freaking guts out, some days she’s fine but then it’ll be one day where she pukes allll day and I’m like is this normal? Can we do something until her OB appointment? Like how do I help her is there any way that I even can? I mean she’s puking her guts out BAD and all I can offer is promethozine and peppermint oil to rub on her stomach. I also made peppermint tea but that only goes so far and im worried she’s going to get dehydrated and end up in the hospital