Just my personal thought, but I would think it'd be fine - is there any odor associated with the glue? I guess I'd just let it air out for a couple days in case.

The glue should be allowed to harden for 24 to 48 hours before letting the gecko into the enclosure. Or is that aquarium sealent? Either way, better safe than sorry.

It will be fine, I would let it air out for a day or two like Nate says just to be safe but the stuff is marketed as non-toxic and I've used it with a ton of different animals with no ill-effects.

Also remember that leachies really don't need plants in there enclosure just cork rounds to hide in so if she wants to remove the plants completly she can.

It should be fine, I use hotglue to seal up the ends of my bamboo.

I use hot glue all the time to secure plastic plants without any problems. To be on the safe side I would just make sure it isn't used close to any extreme heat source like up directly under a heat lamp. Like most adhesives and paints that are normally deemed safe, they aren't usually tested under extended periods in high temperature conditions for toxins or VOC emissions. Also keep this in mind when using any products. What is certified safe or non toxic for humans may not necessarily be safe for reptiles, birds or other small animals.

Thank you everyone for your responses!  I'll let her know then with more confidence.  :)

my leachie - who is still very tiny, so her habits may change - divides her time between the fake plant, the "flat" piece of egg carton, and the toilet-paper tube...so even if they don't "need" it, they'll still use it 

Silicone has to "cure" until the vinegar smell is gone. Hot glue however, is harmless once it cools off. It will come loose under warm/humid conditions over time. The only hazard I could imagine would be the risk of swallowing loose peices, but I've never heard of this. I've used hot glue in many types of enclosures to fasten perches, air plants, etc.    -p-