It’s a waste of time wondering about what she does and why. Focus on what you do and why. You likely still have feelings for your ex and it’s not fair to your current girlfriend. I recommend you stop dating and work on getting over your feelings for your ex. Your ex doesn’t appear to be romantically interested in you, but you are.

I’d stop contact with both at this moment. Your current girlfriend is so called consolation price as you said if not her, you’d be romantic with your ex. That’s not right. Sort yourself out first and then consider dating.