I don't believe she should be lifting weights while pregnant regardless of how fit or not fit she is. I would definitely consult her doctor on this issue. In my opinion, lifting a 100 lb weight is way too much for a pregnant lady to have to handle. As for being fired based on weight restrictions sounds tricky and bordering on discrimination. You might want to consult someone who is familiar with labor laws and whether this would be grounds for a lawsuit should it come to that. Definitely investigate further her rights as an employee. Maybe lifting weights is a big part of her job, but regardless, being pregnant shouldn't be grounds of being fired (which in my opinon, would be a form of discrimination). If anything, her employer should be able to find another role for her to fulfill while she's pregnant. Getting fired is pretty extreme. I agree, perhaps there may have been other underlying reasons why the first employee was fired....good luck!