This is why we are required to use images we have legal permission to use. Zulie didn't have the right to use the photos. If the parents sued, she'd lose. That's what copyright means. Liking and sharing an IG post doesn't violate copyright. Taking the photos and using them on a post does.
The topic of whether it's okay to make money off our kids is an entirely separate thing. Just ask Britney Spears. But we don't get to violate copyright because we don't agree. You know?