Could this be a brain aneurysm?

Last night, around 2 AM-ish, my mother had her (what she describes) "The worst headache she had ever had in her life!". She also felt like throwing up as well. about 2-3 days before that, I had noticed that she had nasea. today, when she woke up, she says it doesn't hurt so much. She is telling me and my sisters to promise her that we won't be mean to eachother, for if she ever dies. Could this be a brain aneurysm?