I know I need to mind my business but...

Okay girls so my uncle had a baby with this girl, and she’s young. She barely knew what to do when she had the baby, which is understandable considering she’s a first time mom. But she’s also one of the type of girls who crave attention and gets mad because my uncle works to support their child. She gets the baby 3 days out of the week and my uncle gets the baby 4 days out of the week. My uncle is completely exhausted, but he always makes time for his kid. This girl posts all the time on facebook how my uncle is a half time dad because he sleeps a lot, during the 3 days she has the baby my uncle doesn’t come pick her up. Mind you he works night shift. she posts all this shit talking about my uncle, but she can’t wait to give the baby to him so she can hang out with boys and drink and smoke. I’m itching to say something because she posts all over social media and gives my uncle a bad image, and people comment telling her he’s a horrible dad because they don’t see what I see all the time. What do you girls think? Should I stay out of it? Or should I call her out?