Responses
I think its more than just low self-esteem. I think our MC is a good person in spite of her shady work. She does awful things for good reasons but she still very much knows how bad her actions are. Part of her willingness to sacrifice herself is to atone for the wicked actions taken in pusuit of the greater good.
Its unfortunate,but while she feels her actions are necessary it does nothing but enforce her already low oppinion of herself :<
"...then even if there comes a day when I must walk the gallows, I'll be able to die without regrets." even after everything she's still willing to sacrifice herself for someone else again, that's the extent of the psychological damage that her mother inflicted upon her, made she think that her life isn't worth much. I hope she can truly change and learn to value herself, she deserves happiness ╥﹏╥