I would say that she is jealous of you and that she is living a life that is not how she really wants to live. This is someone that changed her whole life because her husband had feelings for you. I feel like she wanted to mimic the person you are like copy things about you.
Out of fear of losing her husband she decided to lose weight, dress differently so that her husband would notice her.
Now she is upset that he had feelings for you, so she would have trouble being friends. Basically you are her competition.
You mentioned that you should have said to be friends, but you said nothing. I am going to say that she thought you no longer wanted to be friends with her.
You said about local people thinking she doesn't like you, I don't think they think that because I feel she would not say anything because she has a certain image that she is upholding.
She has told you nothing is wrong and I believe that I am sure certain things have bothered her because he husband had feelings for you, but she has tried to move on from this and change her whole life. She felt that she needed to change things in her life to get her husband's attention.
I would be honest about the flowers and how you feel about the picture.
Maybe she was showing you that her flowers were going to come up nice this year because there was so many buds.
I would talk with her about the picture or comment and see how she responds. Maybe say love the picture, you are going to have amazing flowers this year, their are so many buds.