I'm no fmla expert, and didn't read all post, but I know this. A person I know was on itt. Fmla. Took lots of days off. Company hired a investigator to document persons activities on fmla days off. Person was then terminated for improper use of fmla, lost at arbitration.
So if her child is really sick, and she is caring for them, no problem. But is she was out golfing, sunbathing at beach, whatever, she could have problems.
But like others said, worry about #1, not what others are doing. And she should be also loosing her vacation time and option days. Maybe that would help.
Shotguns don't kill ducks! I do.