It's certainly possible. They lay dud eggs pretty regularly. If she lays a fertile egg, more will be on the way.
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Torey
Eugene, Oregon, USA
1.1 Saharan Uros (Joe and Arthur)
3.0 Mali Uros (Spike, Turtle, and Tank)
1.1 Ornate Uros (Scuttlebutt and Shazzbot)
0.1 Collared Lizard (Rorschach)
2.1 Green Anoles (Bowser, Sprocket, Leeloo)
1.1 Chubby Housecats (Roscolux and Jenny)