How can I stop my guinea pig from being jealous?

So I have a guinea pig named Lucy and she was doing good and all but I learned they do better in pairs so it was a few months later I got another guinea pig named Lily.They're in separate cages because Lucy kept attacking her.About 2 weeks ago Lucy started biting me every time I petted her but she wouldn't bite my mom.Lily really likes Lucy(like Lucy's her mother) but one time we introduced them and Lucy came up to me and whenever Lily came by she would scare her off but now it seems like Lucy HATES me.What can I do to make her like me again & not be jealous?She bites me every single time I pet her.Help me please?No rude comments!