I write training material for a Fortune 50 company, and a lot of it is for our call center. Previously, I was a training/delivery specialist (teacher). Call centers are just a different beast.
The nature of the beast makes it a tough place for pregnant women with extra needs. That's why FMLA is in place. Best advice to her would have been to get on FMLA as SOON as the doctor started giving her special instructions.
The other side of call centers is that it typically is very difficult to fire somebody from that job. There are levels of discipline that must be reached before termination (warnings/escalations of warnings, censures, etc.), at least typically.
Call centers try to control burn rates, because training costs are extremely high.
If she was fired for what is mentioned in the article, it's likely there were incidents before that to put her on an "escalated" status (probably stemming from the extra time off the phone she was taking to use the bathroom).
Call centers are a tough environment and not for everyone. I sure as hell couldn't do that job and am glad I don't have to do it.
"You gotta love livin', cause dying is a pain in the ass."