Lily Mama is interesting. She's a devil through and through, had a daughter with a human man as part of a contract with him. A contract we know now dooms him to hell for all eternity.
With Lily telling us that most devils just see humans as food it looks like she is just married to and had a daughter with a human man for the purpose of the contract and securing a food source. Which like, isn't "evil" perse, just part of how devils work and their inhuman morality. Of course we could still eventually come to find that she's actually got that human love in her somewhere but honestly I'd love to see Lily's mom as just genuinely inhuman and looking out for her daughter (and her daughters future contracts) in her own devilish way.
All in all, while Lily isn't quite ready to form a contract with Mai for reasons obvious to humans, her mom is deadset on making sure her first contract is high quality, and Mai? I can't say she's not.