Jen - my Pip (who doesn't co-sleep really) has started doing the same thing - they're at the age where they realise they are a separate person to Mummy. So some of the screaming may just be that next stage in her development, and not because she's overly attached, IYKWIM?

Having said that, I now bring Pip into bed with me in the mornings only when he's teething - he will smile at me if he's in pain and scream if I'm not there - could Mackenzie be teething at all?

Look luck with it all!