Commenters immediately seized on the baby's position, declaring the 34-year-old "really doesn't care about her child".
"Support her neck she is not able to do it. What if she fell over while you were putting her in this position, she cannot support herself," one wrote.
"She should not be sitting up like that without support at 2 weeks old," commented another.
"Are you rage baiting or genuinely trying to injure your newborn?" questioned a third. "Please research positional asphyxia. Your baby isn't a prop, stop treating her like one."
"Putting your newborn in this sitting position is extremely dangerous," said another.
"You should be ashamed of yourself that you do this to her over and over again even though you've been told multiple times that this is dangerous.
"You do not deserve this innocent child."
"This is EXACTLY what everyone expected of you. To exploit your infant child for content and clout," one commented.
"She's not old enough to sit up unassisted or even hold her head up. You should be ashamed."
Others suggested Malibu was not well and Paytas needed to "get her in to her doctor asap".
Paytas responded almost immediately, writing: "Hey everyone. Thanks for all the sweet comments. I love showing Malibu and what we are doing throughout the day.
"I just said if you're not her paediatrician, to not comment or speculate on medical conditions," she went on.
"She has a paediatrician she sees every 2 weeks in this newborn stage and everything is fine :) she drinks formula and that's why she's got white on her tongue.
"I know y'all are probably trying to help, but medical speculation spreads a lot of false information online. Feel free to leave other new mommy tips and advice, non-medical related :) I always love that".