Translation:She needs to leave now.
Yes, the latter. However, this is due to a difference in what they mean: generally, the former is for something in the line of "basic living necessities" whereas the latter tends towards "intention and interaction", e.g. you would use the former in "she needs water" and the latter for "she needs to leave".
You're most welcome. This is simpler, I think. 必需
An interesting point to note: the difference between 必须 and 必需
They even sound the same (bi4 xu1), so it can be tricky to determine when to use which and it is not surprising to see them used interchangeably with no one the wiser.
必须 - carries a tone of command; used before verbs, e.g. 这个必须带 (you) have to bring this.
必需 - refers to necessities; used after nouns, e.g. 必需品、必需元素 (necessities, vital factors).