I would go with Boma. Since you're picking a restaurant for someone else, I think a buffet would have the best chance of pleasing your friend.
As others have said, most restaurants will make some vegetarian option available. The problem is - there is generally only one option. SO, if that option doesn't float her boat, there won't be much in the way of alternatives.
Boma will give her a lot of options to try. Lots of vegetables, salads, side dishes, soups, hummuses, and lots of desserts! If you make a dusk-time dinner, you can view the animals on the savanna, making the meal more special.
I am vegetarian and I ADORED Boma. My carnivore husband loved it as well. There were plenty of interesting meaty options for him. My picky, picky daughter loved it too. There's really something for everyone.
) so we are always on the look-out for vegetarian meals for her. We happened to like the option at Yak & Yeti (the TS meal) because they allowed us to pay extra for tofu. We also liked the fancy mac n cheese at Chef's de France. It was to DIE for! It came on the prix fixe lunch menu along with french onion soup and a dessert.
