My daughter will turn three next month. She is advanced for her age, most adults believe she is four due to her language skills. We live in a neighborhood where she is friends with a four year old, but constantly wants to keep the friend to herself. She will scream at the friend, pull her away from other children and try to seperate her friend from holding hands with any other little girls. I'm not sure if this is a developmental stage or how to go about correcting this behavior. For some additional background information: we moved to this neighborhood in July, new baby sister at end of August, started Montessori school where she is one of youngest-age goes up to six. I've witnessed her being bullied by older kids at school (shoving her aside, hiding things behind back, grabbing without asking). What are your thoughts?