Hmmm. Honestly, if she's 500 grams, it depends entirely on what she does this winter. If she eats this winter, you can probably get her up to 1200-1300 grams by this time next year. If she's that bit by November, she'll eat her way up to 1600 grams by the time she lays in the spring. If she decides to stop eating, or skates by on a mouse a month like my super mojave did, she might even lose weight. And then she won't be breeding size by next winter.
If I had to put money down I wouldn't bet on her being over 1000 grams this time next year. But I wouldn't have bet on my pastel two years ago, either? And she gave me 6 eggs this summer. If really depends so much on what they decide to do their 2nd winter.