She knew I loved trains and sent me some photos.
Is there a story associated with those photos?
She sent me a picture of my ex-girlfriend next to a train. I think she is jealous.
Doing things to remind your partner of their ex can be passive aggressive. If you have an issue then you should try talking to your partner about it. If you continue to be upset over something it can cause tension in a relationship.
I know I should try to talk about, but it's just not worth it.
I would highly recommend you do talk to her about it. Communication is healthy and could solve a lot of problems.