Hard to tell just from size, but I'd agree with Jeff's guess too - if she's a normal feeder.
Just to show the range in growth rates in hondos I've got an 18 month('03) female brumating right now at 650g, along with 2 clutchmates at 400g and 550g. At 8-12 months old, that girl was easily close to that size, maybe bigger(She started on adult mice at 6 months old).
I've also got an '03 brother/sister pair who are both under 100g. If she feeds like those 2 do, she could be 2-3 years old. I highly doubt she'd be older than that though.
Those are just two of the extremes I've seen in my own collection, but it goes to show how difficult it can be to tell just from guessing on the size.
She looks like might make some fine Tangerine Albinos though. She doesn't seem to be tipping all that heavily, so you might get some nice clean offspring..