Trust and grief
Congratulations on identifying that the thing that's missing is trust!
Like the girl you are in love with said, she has been hurt. However, what she might not realize is how heartbreak makes us doubt ourselves and our decision-making process. She may not trust herself to pick the right man; especially while she is still grieving.
It is good that you have made your feelings and your agenda clear. You are in love with her, and you want to be with her.
Because she is not ready to be in a relationship with you, is there another option that works for the two of you?
If you can, offer her your friendship. This will give you a chance to get to know each other.
The only way to build someone’s trust in you is to be trustworthy and reliable. Keep your word and all the promises you make to her. That includes seemingly small things like calling when you say you will and turning up on time.
Women also open up to communicative men who are open about themselves and willing to listen to us. Let her share what she is going through and help her on her journey of getting over the heartbreaks of the past.
You could try new things together so that she begins to associate ‘safety in new experiences’ with you. You must also respect her ‘no’ if and when she says it.
Keep in mind that there are no guarantees. She may get over her ex and start dating other people. Or she may not be able to build trust for you. That will hurt you.
Only you can decide if she is worth the risk of your own heartbreak.