Thank you for clarifying.
It would be preferable to talk to her in person. She already knows where you stand in this based on the messages you've shared with her. She would need to see some changes in your behavior if she is ever to reconsider getting back together.
When you see her in person, ask her what are some of the things she would like to have in a relationship. Together, go over the factors that led to the drifting apart in the relationship after you were released from prison. If there were things you were responsible for, let her know you accept those mistakes.
All relationships have some ups and downs. What makes some relationships last is the ability of each partner to work on those issues. It is possible that you've grown apart because the two of you had changed in some ways. If one person is not ready or willing to deal with the others changes, that may cause friction.
Hold onto sending flowers and try to focus on open communication w her and best to be done in person. You could write down some of the things you want to talk about and also ask her to do the same so the time you see each other is utilized appropriately.
She may be cautious now and not wanting to get hurt or disappointed and may seem distant emotionally because of that. Give her some time to deal with her feelings.