My iggy is almost 11 and is definitely a female. She has never laid eggs. She's gone through egg season many times. She gets restless, digs, goes off of her food, and gets a very swollen belly full of eggs (we've had x-rays to confirm). Instead of laying she always resorbs. Sometimes she gets a little orange on her front legs.
Many girls do lay but some just resorb. It's a good idea to have a vet check out your IG during egg season and provide a dig box just in case. She's never laid but we still give her a box in the event that this might be the year she does lay.