How do we know her log hair was a wig??? I really don't think so... Kate Mulgrew did other movies around that time her hair was long in those.
No, that was a wig. She's on record on about this one. He hair was very long like that when she was in her teens and very early twenties, but it was just at her jawline during "Caretaker", and the bun we see is a wig/hair piece. Anytime we saw that super long hair, it was a wig.