3 yo older sister screaming and throwing objects left right centre

[Manoxlon]

Help! I have 2 kids- 3yo dd and 1 yo ds. My dd has recently become quite aggressive whenever she gets frustrated eg when she can't fix a toy or do a drawing the way she wants. She screams, and had today started to throw her toys to the wall. I have never seen her in such a state and I am very concerned. Not sure if it's jealousy (she has not really been jealous of her brother, is it coming out now?) or is it a normal part of 3 yo development? HELP, please!