Thanks for your input
I would wonder how happy Newt would be being kept indoors permanently? If she's happy, then I'm happy - that's all I really care about. But getting her to that state is my current challenge. I think she might wear down my resolve before I wear down hers
I just wish there's a safe way to get her spayed sooner (rather than having to deal with this behaviour for another two months) - the vets I have spoken with indicated I have to wait another few weeks after the kittens are weaned, since her glands will still be inflamed at that time.
In case anyone's curious, I have a few photos up on a personal gallery I have:
http://www.pbase.com/auriga_m38/newt