I hate when people use the excuse "but she is a mother, now she is a mother without a job!"
Same could be said for fathers too, but hardly anyone does unless it was a single father. If her kids were that important, she shouldn't have been breaking the rules. Trying to find a reason is a dick move, but no matter how well I work at a company, I always do my best to make sure I follow all the rules regardless how much leeway I could have. The moment someone doesn't like you, bam out you go.
I got let go once because I was HELPING our company tech support, by plugging my laptop into the router, apparently a security issue, even though that router has free wifi -.-. Just cause the manager didnt know what the hell he was talking about.
Your kids are important, but shouldnt be used to get your way. She was in the wrong.