Squeals and screams

I have a squealer!  Molly is a happy, content baby but she has now started squealing when she wants something...back to my book by the Pearls, Huh!  Anyways, I think she is in a growth spurt right now, because she eats all the time...she squeals when she wants more food and it is so loud, so annoying, and so disrespectful.  She also hollars/squeals/more or less yells at us when she wants something (toy), when she wants to exert her independence, or is not happy about something.  So John started flicking her in the mouth and saying "NO", I am trying to teach her some sign language like "more" and "please" and I say "No" in a stern voice.  She wants to be down, exploring all the time.  She isn't one that has to be held or rocked and she is not real needy, but she KNOWS what she wants!  I blame John...he said when I was pregnant that it would be nice to have a child with a spunky personality.  Well, I believe his wish came true!