Yes happens to me too! Ever since I was a little girl. I think it's basically because I am a nice person and they see that in me. Also might have something to do with me being an only child.
Another things is I have a round face, so maybe something like that draws a child in. Similar to baby cheeks? Not sure though.
I think this connection with children, had some input into to me wanting to work with children, which I do now. Kids do like me that's for sure
I had this really nice moment with a child recently where I work, I have this little boy who never seems to talk. Then one day out of the blue he just started speaking to me, chatting away and giggling. Those sort of moments are just beautiful.