I was tired my entire pregnancy, but the first trimester was by far the worst.

I'm a retail manager, so I really wanted to stop working early, but I knew if I did I'd be bored out of my tree. All I would have done is eat and sleep. So I kept working, I'm glad I did though, because I get a year off, and unless I change jobs, I get to be home for my sons first birthday.

So if she wants to work, she should work. The only people who get a say in it (I understand your family is just trying to tell her she doesn't have to if she doesn't want to work, not forming her not to) are the couple having the baby. She may want to wait a few more weeks to see how she a feeling, because she may get her energy back.