4 year old with crazy trantrums

For the past 4-6 months my 4 year old daugther has been having a lot of tantrums, doesn't listen, and is contstantly saying "no".  She can be the sweetest girl sometimes and then can instantly change like she is possessed!  we just had a baby one month ago and we are doing everything to make sure our 4 year old feels included and still gets a ton of attention, and some mommy time.  Our discipline has been time outs and taking things away - like watching TV or treats, but nothing seems to work.  I am contemplating a rewards chart so that it's more positive reinforcement of good behavior.   Please help me come up with a solution so that she doesn't have a tantrum every day anymore.  Thank you.  

[margypops]

This is so normal, she feels usurped and even giving her plenty of attention wont stop the feelings she has, having seen this myself I know one has to ride it out, you are doing to right thing in focusing on her positive side with lots of praise . Now I wonder if when she has a meltdown' you ignore it, walk away ,no reaction as sometimes they do it to get attention.Ignore the word No ...could she have got that from you saying it to her ? just a thought so lessen your No's ..children copy us in all things .It will pass keep doing what you are make sure she is not left out and walk away from tantrums ,dont feed into them ..good uck.