Oh yes, that is absolutely a possibility that a lady chow hound will scarf it all up and then tromp the rest....lol....crazy rufians...You can offer fresh clipped cuttings from your plant...or you can drop some seeds into her enclosure and see if they will provide some snack time.
You could also plant some in small flats and rotate them out from a sunny growing place to the enclosure every couple of days or so...this though should be part of her diet and not the sole item...although wheatgrass with my Redfoot tortoise is like a crazy disappearing act ....*that circus music song playing here*
Yes, Russian tortoises will include a little bit of grass in their diet, and wheat grass is one way to provide that. I have fed my Russians wheat grass, and they did eat it, although in my case, the female ate more than the male.
Bear in mind, Russians feed on grass a little more than other Testudo species, but they don't graze as much as larger species, such as sulcatas, leopards, or Indian stars. This is probably because they are too small to house the long digestive tract needed to break down grass thoroughly. Grass is more fibrous than herbs or shrub leaves, so it takes a very long gut to digest it. Big tortoises can house a longer gut inside their body, so they can eat more grass (although they still need herbs in their diet, too). Small tortoises like Russians, though, cannot afford to eat too much grass, because much of it would pass right through them.
Grass is still good for Russians, as it does provide needed fiber, but their diet should still consist primarily of leafy greens, like lettuce, dandelion, escarole, kale, etc.
That I don't know. I have heard of people giving squash occasionally to their tortoises (usually sulcatas, it seems). However, I don't know how often they do it, or whether it is advisable or not.
I can tell you that I never give squash to my Russian tortoises. The only fruits they get on occasion are cucumbers, tomatoes, strawberries, and grapes. And again, this is a very rare treat - probably once every two months or even less often, and only a little bit at a sitting, because it doesn't take much fruit to disrupt the digestive tract and gut flora of a strict herbivore like a tortoise, and give them diarrhea. Not the end of the world if they get diarrhea once, but it should be avoided, and certainly if it happens repeatedly they could become dehydrated, or have blooms of parasites and the wrong intestinal flora. BTW - They don't seem to be that crazy about these fruits anyway. Seems like the thing that gets them the most excited is when I switch them to a type of leafy green that they haven't had in a while.
I'm curious to hear from people who do use squash, and how often they offer it.