Giving 1mo old a taste of ice cream

So I’m pregnant but my sister has a 1mo old and she gave him a taste of ice cream…. I thought this was the strangest thing ever and I don’t know why but this worried me. He isn’t my child so I didn’t say anything. But will he be affected in anyway? Obviously it’s not okay for a 1mo old to have ice cream (even tho it was just a little drop)