She wabts to try with her ex

Hi

A woman i work with directly have been seeing each other for 3 months very casually, we have slept together a lot too. We have an amazing connection and we both expressed how we felt about each other and its mutual.

Suddenly her ex came back into her life and want her to give him a chance. After a while of her contemplating she has decided to give it a chance saying that she needs to know or she will always wonder.

Should i wait for her? Or should i move on? Also want to do no contact but i work with her and that is hard to do or hard to be around her.

I need advice