The lady we bought her from at the reptile expo said she's about one month old, and she'll be full grown in seven months, when she'll be about seven inches long. (She also sold us 500 crickets for $9, which considering Willa's previously mentioned eating superpower, was a great deal. We'll be looking for more of those good deals, as Willa is not going to be eating a whole box of crickets from the local pet store each day--at $3 per box.)
So welcome, Willa. I hope you live a long and magnificent life. I vow to keep all rubber lizards far from your delicate (voracious) jaws.