Hello,
All I can tell you is what my experience has been, and frankly it's just not that much. I have had only 2 liitters, but I am pretty observant of my creatures.
My female does not eat while gravid, although I offer her a rat every week or two. She will not even eat a smaller prey item during that time. Her temperment stayed relatively the same until the week before she actually gave birth. She sought out warmer places and positioned herself differently during the last 2 1/2 to 3 months. She layed on her sides more often during the gestation. Almost everytime I took a temp gun to her she was 80 degrees, no matter where in the enclosure she was. She was obviously larger starting about 1/3 of the way down from her head to about 6 inches up from her vent area. She seemed more inactive than usual meaning that even in the wee hours of the night she didn't become active as my others did. She did everything else a bit more slowly like take longer soaks when she soaked, stayed in the same position for days, and changed places in the enclosure much less often.
She took longer to shed, and the actual process of the shed took much longer also.
I live in Texas, and it seems to me that if your female is gravid you must live far, far away from me because it would be a really off time to have a 4 month gravid female at this time. That would put her about end of December to lay, and that is far off the time babies would be born. I have a pair of BRB's that must have been born in Nov or early Dec '03 so it's certainly possibly but unlikely.
The appetite alone makes me think that there is sometime other than being gravid going on. When was her last bowel movement?
Are her urates being expelled regularly? Has you husbandry changed recently? Could anything else account for her situation?
Linda