Dealing with your girlfriend's shadow over her ex-boyfriend may require some patience and understanding. Here are some suggestions:
Listen and understand:Give her plenty of space and time to talk and let her express her feelings and emotions. It's important to listen and understand her feelings, not to question or try to solve problems.
Don't compare or criticize:Avoid comparing her ex to you, and don't criticize or blame her feelings. Respect her feelings and give her support.
Build trust and a sense of security:It's important to build trust and security in relationships. Through her support, thoughtfulness, and understanding, help her gradually overcome this shadow.
Encourage asking for help:If her shadow has a serious impact on her daily life, she is encouraged to seek professional help, such as counselling or**.
Give time and space:This condition cannot be fixed overnight and takes time to heal. Respect her emotions and needs and give her enough time and space.
Actively build healthy relationships:Build a healthy, stable, and loving relationship where she feels supported and secure from you.
Dispose. 
Understanding, patience and support are required. In this process, it is important to build trust and communication with each other, so that she feels supported and understood.