Sorry if you are having problems with the site. I'll try to answer your question with the information I have, as you should get your money's worth!
If your goat is new to the diet she is getting, she may be adjusting to the new diet. If not, and this is a new development, she may be experiencing some minor bloat, causing an acid environment in her rumen. If so, your friend was correct in telling you that baking soda can help. Baking soda acts to neutralize the acid in the rumen, getting the rumen pH back to normal. It's difficult to guess the weight of your goat, as less than a year could be from a few to 11 months, which is a wide weight variation. One thing you can do (which I do with my own goats) is to provide an open box with a box of baking soda dumped into it. This allows her to "free feed" the baking soda, and goats will usually eat the amount that they need. You can also dissolve baking soda in water and give it to her using a large syringe or turkey baster. I would recommend mixing approximately 10 tablespoons with 1 cup of warm water. I would also recommend picking up a product called "Probios" at your local feed/supply store and giving her the amount suggested on the label for her weight. This product contains natural micoorganisms which can help to return the rumen back to normal function.
And no, your goat will not die from throwing up her cud. The only danger here is if she were to accidentally inhale some of the liquid into her lungs, she could be susceptable to contracting pneumonia. Also, if she is vomiting large amounts and unable to hold any feed down, she would eventually become dehydrated. If this were to be the case I would get her to a Veterinarian immediately. Hopefully, this is not the case with her.
I hope this helps you, and that you receive this answer. Please let me know if I can help further.