generally eating the plants in their cage can be caused by a number of things:
them needing more water, check her urate, it should be white if its yellowish she needs more water, more frequent mistings or a dripper so she she can drink whenever she wants to
them wanting to try plants, there are alot of plants veileds can have as treats once or twice a week as they need to be getting their nutritients from their feeders and supplements, check out this thread for a list of fruits and veggies your friend could try as treats https://www.chameleonforums.com/fruits-veggies-feed-my-veiled-cham-103071/
they still may not be safe, we should check just to be sure! oftentimes pet stores are not as educated as they need to be on everything they sell unfortunately. this is a safe plant list for chams, https://www.chameleonforums.com/live-plant-database-2632/ i would check and make sure your plants are on the list that way she isnt chewing on something that could be toxic to her.
you dont sound stupid at all, very common question urate is the "pee" part of her feces. the brown part is feces(poop) and the white part is urate(pee). her urate should be white if she is well hydrated. if it is yellowish she is not getting enough water and this may be a reason why she is eating the plants. what do you do for her for her to drink?
i just use a squirt bottle regularly and she seems to just go about and drink all the water beads that are left on my bamboo grass and other branches, but i will be sure to look at her urate next time