Hello, has your older daughter been increasingly aggressive for over t...

Hello, has your older daughter been increasingly aggressive for over two months now? She is 3 years and 8 months old, and her younger sister is 8 months old. She exhibits aggression by screaming in a sharp voice and scares her younger sister. If you ask her something, she might say "no" in a scream and also scare her. Recently, we sent her to daycare thinking it would distract her, but when she comes home, she cries and throws tantrums without any reason. We pay attention to her and play with her, including running around outside. She used to be very loving and helpful before, but now she's completely different. I don't even recognize my daughter anymore. We explain that she shouldn'