bun in oven

my best friend is pregnant, which is very exciting. she's also suffering horribly with morning sickness, which is not so exciting. i've never been knocked up, so i have no advice to give her about how to alleviate it. do you guys have any ideas or experience with it? is it different for everyone? any food in particular that you found wasn't so tough on the tummy? p.s.-she's vegetarian.