i bought dummy eggs as soon as I decided to buy my tiel from the breeder. I did that because like Zara said, egg laying might be thwarted if you give the bird 4-6 extra dummy eggs after the first egg is laid. If she does lay an egg and you don't have dummy eggs, make sure to leave the egg(s) with her until she grows bored of them, otherwise they can lay more eggs to replace eggs "stolen".
I've read it is extremely rare for a healthy and active tiel to become egg bound. My tiel gets hormonal quite often ( she will stick her butt in the air) and I just distract her . She only does that while in the cage. Sometimes I wonder if it is just to get my attention at this point, lol. It happens probably every 2-5 days, except for when I move her to a new environment ( My family or boyfriends place, then she remains non hormonal for three weeks ). If you notice hormonal behaviour just try your best to curb the hormones. Changning the cage layout, toys, cage position, giving the bird more foraging options, and just hanging out with your birb often enough can distract them from being hormonal. My tiel has been hormonal since she was only 6 months of age, so I Had to be more vigilant about toy placement to not touch her back, but still , at the age of 5 1/2 , has not laid 1 single egg. I never had to use a dummy egg , yet.