At this age, your kid is having a hard time in identifying various emotions. She may need help to identify them and talk about it. Most of the time she is not able to judge how she is feeling and how to express these correctly.
What you need to know:
Now, your child wants to do things perfectly be it a game, school activities or personal chores. This results into different emotional challenges like, 'I have to win that' causes anxiety, 'I am not doing good' results in sadness, jealousy or frustration, 'friends or parents not listening to me', your kiddo shows anger, insecurity. She might hit or bite someone or busted out into tears. All these feelings are a natural move towards the next level of childhood. You should make a practice of naming the feeling, label it while you talk to her. For example: 'Today is your first day at school, you are excited', your friend is ill, you are sad'. This will help your child to understand feelings. Talk about ways how to tackle particular feelings specially anger, frustration and jealously.