I'm not sure how big the old girl is. I believe she was 11 or 12 feet the last time we were able to stretch her out. She's become a two person snake simply because of her weight and strength. But she's not aggressive; most boas are pretty laid back.
If I weren't so busy, I'd volunteer at a local park where they have a 12-foot burmese and a boa. Volunteering there would give me a chance to work with the big guys without having to own one myself and without having to find someone to be my partner when I needed to work with one.