If she has enough of a personality to be upset over this type of thing wouldn't that imply that she's very powerful, and wouldn't want to share you with another powerful spirit?

[ It only makes sense that she would be Lex's most powerful spirit companion. ]

Would she really be upset with you sharing a Familiar bond with someone like me? I can't compare to a great spirit like her, so there is no reason for jealousy. It would be like being jealous of an ant.