I would say you are probably right about the jelousy thing. Still, it might not be that she is wanting to prevent you from holding her baby sister, it could be that she simply wants attention and she feels this is a good way to get it. When you had the new baby, her world changed forever. Not that it is a bad thing, just a huge change for her. My suggestion would be for you to schedule "sister time" when the girls are allowed to interact closely and under your watchful eye. Give the older girl a chance to bond in an appropriate way and let her know that there is a correct way to "play" with her baby sister. Maybe she could read her a book. Maybe she could help with bath time. Whatever you feel comfortable with. In addition, I would also schedule 30 mins everyday that is just for her (the older one). Once the baby goes to bed, do you have time to do a fun activity with the older child? IF so, make that your routine. Let her know that just because the baby is here, you still have time for just her. Good luck!

Screaming at her is definitely the wrong reaction. Stay calm. Make sure that she is involved in caring for her baby sister as much as possible, maybe helping with changing the nappy or fetching a drink or tidying the nursery. Perhaps sometimes you could say something like 'you can't pick her up right now but you can sit in the playpen and play with her toys with her for a while'. And make sure there are times when she can under supervision pick up and cuddle her sister. If you just scream at her for showing the baby affection and punish her, then she will start to resent the baby. Sending her to her room is isolating her from the family unit, she will feel rejected. Involve in everything as much as possible. Get her to help you with the housework in little ways too, being mummy's little helper. Like the last reply said too, make sure you put time aside just for her each day, even if its just a story at bedtime. Make sure you give her lots of cuddles as she is obviously a physical child. I really don't think you have a problem as such, just how you handle it could create a problem.