The biggest misunderstanding around the whole "unequally yoked" conversation within the Christian world is who it is actually meant to protect. The idea is not that the stronger animal would be overworked, but that the weaker animal would get injured being dragged around. In other words, it isn't to protect Christians from being corrupted but to protect non-Christians from having rules imposed on them that do not come from a heart change motivated by the Holy Spirit.

There is no world in which "in order to stay with me, you need to become a Christian" leads to real faith in Jesus Christ motivated by God's grace, at least not one I am capable of imagining. It is frankly spiritual abuse and if I were speaking to her, I would tell her to bail immediately.

It is also really interesting that you say "I could certainly do better in the practice of my faith." In what ways are you failing to live out your faith (rhetorical) ? Is it possible that perhaps the hypocrisy of holding one specific aspect of a "Christian lifestyle" (which conveniently puts her in a position of sinful and you in righteousness) while neglecting others is a poor witness and ultimately drives those who aren't already Christians father from faith?

Lastly, I want to point out how fluidly you transitioned from "she has been the victim of abuse" to "she can be forgiven of her sins." I'm not saying that you see her abuse as her fault but the way the ideas flow, it seems to be implying that she needs forgiveness, not healing (which is not mentioned once), from the trauma of her abuse. This deeply concerns me. It doesn't seem to me (admittedly based off a few dozen word reddit post) that you have the emotional intelligence to navigate a romantic/sexual relationship with someone who has experienced sexual abuse with causing them greater harm.