I got a new tiel about a month ago. We named her Izzy. Well, we think she's probably a she anyway. She's only a few months old, so I suppose it's too early to really worry, but recently she started pulling the paper up out of the bottom of her cage and shredding it. I know it's normal for birds to chew on things (My last bird chewed through his perches!) but I lost my last female to egg binding, so I'm concerned. Is there any way to guarantee that she won't want to lay eggs?

I know that limiting light helps, so we have a blanket that we wrap around her cage after she's had 10 hours of light. She doesn't always go to sleep, but she is in the dark. There are sounds in the room though. We have a small place, so unless we carry her cage to the bedroom every night (which would be a pain, because it's quite large), we can't put her someplace with no noise. Our male never started breeding behaviors when he was in the same space, so I'm hoping it's okay for her too.
We know not to pet "below the belt" but one site I saw said that even head petting can make them think you're a mate. I certainly hope that's not true, since she loves getting attention, and we love giving it to her. We know not to give her any bird-shaped toys or mirrors, and she has no nest-like areas in the cage. Another site said that more fruit and vegetables with less protein helps too. We fed our other bird Roudybrush pellet all day, with vegetables, grains and such 1-2 times a day, so that's what she gets. If we need to adjust her diet, we can do that. I also read that changing things around in the cage regularly can make it seem unsuitable for nesting. Is that true?

I feel kind of stupid for worrying about this with a bird that's only four months old, but after losing my sweet Cherie to egg binding, I guess I'm just a worried birdy momma who'd rather be safe than sorry. We kept a male happy and healthy for 13 years, so if she turns out to be a he, we'll be all set. If she really is a female though, I want to be prepared.
Thanks in advance for any advice.