Leading off another question.. can a child know i'm pregnant before I am?

Another woman posted a question like this and now I'm thinking.... I am TTC and hoping to get a BFP on a test soon and I was at my friend's house with her 4 y/o daughter. I have never said anything about TTC to friends/family and she came up to my and whispered "will you have a baby in your tummy still at so-and-so's wedding?" I almost fell over.... and then I blew it off.... can children sense it??? I haven't even confirmed it yet....