Do remember, she spent centuries as a sword where her only emotions for the longest time were sorrow/guilt over the deaths she caused and hatred for what was done to her. And despite being reborn, she's made it clear her mind is still very much in that mind set, the poor girl hasn't regained her other emotions back yet. She doesn't recognize that the ml likes her because she doesn't remember what that means. One could even argue given how she lived as a child in her first life, she never really knew what it was to begin with and to then spend centuries being treated as a killing tool? She doesn't know, so while I can't wait for the two to end up together I also understand why it'll take time. I'd rather they finally become a couple when she can feel love versus doing so simply because it makes him happy.