The weight she's at is the normal time a lot of females hit the wall persay. We hate it but many females hit the 1000 gram wall when we are trying to get them up to weight for breeding. They are notorious for going off feed right around the 900-1200 gram point. There isn't much you can do except to keep offering weekly until she decides to eat again.

Try some of the tricks of the trade.. Change the bedding in the enclosure to something different. Take her for a long car ride in a tied pillow case. Offer her something different to eat. Offer her a smaller food item. Maybe you'll get lucky.