Hi,
My dd (2.6 years) has me at my wits' end shouting over me when I talk to her dad or friends who come to visit with their toddlers. Sometimes it's really bad and she shouts practically every time I try to talk to her dad. She's started to say "Mummy no talk papa" or "No mummies" as well when I'm talking to dp/friends. 
I talk to her a LOT, and look after her full time, so I don't think she gets too little attention in general. I've tried explaining that mummy is talking to papa/friend, that she should wait, that I'll talk to her after, that we talk a lot but mummy has to talk to other people too (but she just says "mummy talk to me"!) and I confess I have shouted "DON'T SHOUT" at her when she has really gone on and on shouting loudly every time I try to open my mouth. She has a new little sister of 9 weeks and is still a bit jealous, but she did the shouting before dd2 was born too.
I'm just at a loss to know what to do about it - any ideas?? TIA!