Your girlfriend is definitely feeling a bit insecure, but it’s also possible that you are making time easily for Jane and not your girlfriend. It’s tough, because speaking with Jane is a new work relationship, while a conversation with your girlfriend is an already developed and established relationship. There’s nothing wrong with how much you talk to Jane but you do need to be understanding of how it is making your girlfriend feel. I suggest a mixture of both attempting to be done with work earlier (if possible), and also being a little more engaging with your girlfriend and her life. Finishing work earlier will definitely be noticed by your girlfriend. Also, I don’t recommend trying to have a conversation trying to defend Jane while your girlfriend is currently in this state.

Basically, you’re not wrong for what you’ve done, your girlfriend isn’t either, and you just have to find that happy medium.