I don't think its CMPA as theres no mucus or blood in her poop, just that there's an uncomfortable nature to her she'll cry when farting etc, I didn't know Lactose intolerance was rare in babies! My sister had it when she was a baby so it's all I've known Thank you @Genevieve
It’s probably teething. Poo always seems to smell more acidic when teething.
The vinegar smell can be teething related. An allergy would likely be cows milk protein rather than lactose intolerance as that's very rare in babies, but if she doesn't have any other symptoms it's less likely