Why Is my 3 Year-Old So Aggressive?
«Why is my 3 year old so angry and aggressive? I did just get divorced from her mother, but I feel like this is very out of the ordinary for little girls.»

It is not uncommon for toddlers (or children of any age) to change their behaviour when they go through a big change in their life, such as their parents’ divorce. Your 3-year-old may be finding it difficult and because she lacks the ability to verbally express her feelings, she might be expressing them through her aggressiveness.
Whenever she behaves in an aggressive way, gently tell her: “No, you cannot hit/scream/bite”. Tell her every time she behaves that way and with time she will likely change her behaviour. It is really important to be consistent and always tell her this when she behaves in an aggressive manner. Ideally your ex-partner should use this same technique.
It is also likely that as your toddler gets better at speaking, she will no longer have the need to behave aggressively. Sometimes, toddlers behave aggressively because they get frustrated when they cannot convey their feelings and thoughts to us.
Finally, consider that children learn mostly by observing how their parents behave. So, it is important that you and your ex-partner do not behave in an aggressive or angry way. Try to be a good role model for her.
I hope this information is useful and wish you all the very best. If you need some support through the divorce, please do not hesitate to get in touch with me.
You may also find these articles useful:
Should We Divorce or Stay Together for the Kids?
How to Explain Divorce to a Child?
Fostering Emotional Competence in Children: A Guide for Parents
Tips on Toddler Aggression: When to Worry?
I hope this information helps. I wish you and your family all the very best,
Love,
Ana