While I don't think it would HURT your snake to try and breed her this season, I usually use the 2 year mark. These females are about to go into their 3rd winter but I start pairing early.

Breeding her this early will probably give you a very small clutch size. There is an article out there somewhere but I don't have time to find it. I'll look when I get home today. Basically the article states that in that author's experience breeding females for the first time when they had gone through their 3rd winter produced normal to large sized clutches, while younger females of the same weight or lighter females produced a smaller clutch during their first breeding season. The females that laid a small clutch continue through their breeding career to lay very small clutches in comparison to females that had waited to breed.

So my advice would be to give her at least till next season. By then she should be huge and should produce a nice big pile of eggs for you.