You gave it a good go and have decided it isn't for you.
If it is still for your co-founder, thats fine - it sounds like she is the one with the debt anyway?
There is not point in haggling for equity if your company isn't profitable - it's worth nothing and you have decided you don't have the resources to make it profitable.
If you're really worried about it becoming something in the future, then perhaps you're not done yet and should regroup or pivot the idea.
You can't have your cake and eat it.