None of the many female burmese I bred back in the 1980's and 1990's ever showed interest in food after ovulation. I was quite certain they would not feed, but it was a good confirmation of being gravid. The typical period from ovulation to prelay shed was 18 to 24 days, so your female seems to be fairly close to that range. If they are gravid, after the prelay shed they will begin to swell significantly over the next few weeks and you should start seeing the typical inversions. Laying will occur 25 to 30 days after the pre-shed. Good luck with her.

Kelly