Old wives Tale?

I thought my mum was the most superstitious person i had ever met. i mean when she came to visit she had all these ideas about babies and how to treat them. she believed that if your baby does something positive, you do not praise the baby rather you say it in negative terms. for instance she didn't want me to say my baby was a big baby becos saying that will make the baby skinny! (yeah ! right) im sure its the most ridiculous thing you've heard right?. well i think i'm starting to believe some of these tales or is it just coincidence? any time Nana does something positive like say she sleeps thru the night or she eats very well in a particular day and i blab about it to my friends, she will unleash her worst behavior either by not sleeping at all or cry when im feeding her. i was blabbing to my friend about how Nana was doing and that very day she woke up and won't sleep for hours! is it a coincidence or what? so now my approach is to be passive about her oh well! lets wait and see