I do not plan on cooking any differently for my girlfriend.
Why would you not cook differently for your girlfriend?
I would just rather making one thing for dinner instead of two separate meals.
While I know that it can be very demanding and overwhelming for you to cook two different dishes for dinner, your girlfriend might have an underlying condition that prevents her from eating what you are used to eating. If you really do not want to cook for her, you can try and ordering something online and try to order her food that she can eat.
It's difficult to cook a separate dish.
If your partner wants to eat a certain way than you are better off trying to accommodate for her. She has the right to choose how she wants to eat, so if you do not follow this choice she probably will not eat the food anyway. In addition to that, you are doing a nice thing for your partner which I am sure she would appreciate from you.