I don't think you are saying the 'wrong' thing. Oftentimes examining / analysing the transference (which can be revealed by fantasies and dreams as well as "real" interaction) is the way forward...

I think that your therapist might have been trying to give you a lead in to your telling her what you wish you had when you were a kid. Identifying what you felt you missed out on can enable you to grieve for that and also figure out how to meet it in real world relationships (not just with your therapist but outside therapy as well).