Behaviors what’s normal?

What is normal behavior for a 7 year old? My daughter will get very upset over the least little thing. Something doesn’t work right or something and it’s crying, screaming and jumping up and down. She’s been in OT to help with calming strategies and so far it doesn’t help and seems to get worse. She can be mean to her brother and I understand siblings do this, but he’s delayed and non verbal. He can be minding his own business and she starts with him. We’re all at our wits end and I feel like I’m just failing. I’ve tried to get her in to talk to a professional, but everyone is booked up. Any advice?

I also want to add we have tried taking screens away, keeping her occupied with different things, we’re cutting our food dyes and she rarely has those anymore, we try to have a lot of one on one time with her. She’s also not like this all the time, but when she is it’s awful. Almost every weekend she is like this unless one parent takes just her out to run errands or do something fun. Most of it is when she’s around her brother, but then she can be so sweet and helpful with him