But, she has some very valid (in my opinion) concerns about this:
1. Can she even take a semester off, given that she will be a new faculty member?
2. If she can take the semester off, will this negatively impact her chances for tenure?
3. If she cannot take the time off, will going on maternity leave so early in her career look bad and, in effect, negatively impact her chances for tenure?
4. Who should she ask - the department chair, HR, etc.?
She should start by looking at the faculty handbook, and keeping her eyes open around the school. That will give her an idea of the official and unofficial rules. If she's been there a year, she'll be eligible for FMLA.
Personally, I think anywhere between the second year and the year before tenure is about the same with respect to impact on tenure chances, looking bad, and so on.
She could maybe ask HR. She shouldn't ask her chair. Here's why: babies tend to be unplannable things. Maybe your friend will be that lucky one who can decide to conceive in March for a January delivery. Maybe she'll be like most people, able to conceive with a reasonably healthy pregnancy, but not able to time it exactly. Maybe she'll get pregnant next month (oops!). Maybe she'll have complications that will entail going on disability halfway through the pregnancy. Maybe she'll go through the hell of fertility treatments. She just doesn't know. By talking to her chair - unless they are VERY open and sympathetic, and it will take a while to suss that out - she just expands the time frame for possible negative ramifications and awkward conversations.