2 year old afraid of babies

My daughter gets really anxious/upset around any kids or babies smaller than her.

She def is a Covid baby, wasn’t around many kids or people for her first year. Now she’s been exposed to a lot more people/kids/babies.

She seems to like older kids, but anyone smaller than her she is afraid of

She will be ok with them until the other toddler or baby makes a noise. Even if it’s happy noises, it will set her off

Her cousin who is a year old has stayed with us over the weekend on several occasions with her grandma.

Theyll he playing together well the first hour or so then her baby cousin will get excited and start making happy sounds and my daughter gets terrified, like literally having a meltdown. And that will set her off for the weekend. Anytime she hears her cousin make any sort of noise after my daughter starts yelling. Like I’m not exaggerating. Every time! It is exhausting when she’s in that mode

We were just at the park and there was another 2 year old there and he walks up to her and they’re both just looking at each other and my daughter smiles at him then walks back to me smiling all shy. A couple mins later she walks over to him smiling and he says “hi” and she gets all nervous and runs to me

She isnt saying many words (she’s on a waiting list to start speech therapy). She has always been the most careful and thoughtful baby and even now. I don’t believe anything is wrong with her or anything like that. I kind of feel like she just knows babies are unpredictable so it makes her nervous? And/or it’s social anxiety? Bc she only does this with those who are her age or younger

I’ve just never heard about this or met another kid who does this!!