Looks like you won't have to worry about resourse gaurding which is very good. But I don't want to speak too soon, she is still young!
Cookie never had a problem with us taking things away from her either. Since the day we brought her home, we taught her 'trade'. Everytime we took something away from her, we always replaced it with something else she would like so she would learn that nothing bad will ever come of us taking things from her. She's become so good that if she picks something up off the ground, I can easily open her mouth and take it out and she has no problem with it. She actually kind of prepares herself for my hands in her mouth, like when I wipe away her eye boogies. I say "Let Mamma get your eye boogies!!" In a real happy tone, and she kind of squints her eyes at me and holds her face toward me, it's so cute. Like she's saying, "Ok I'm ready! Wipe away!" But she never had an issue with us taking things from her. The only time she wouldn't leave something we asked her to was when she got a dead bird on the street, but our fault for not paying attention. I am always on the alert since I walked dogs in Boston and you wouldn't beleive how many chicken bones are just laying around! I have no idea where they all came from, but they were everywhere! Walking a Beagle on trash day was always a chore and a half! :-P So I am always on the alert, but Jason was walking her that morning and he didn't notice it qiuck enough and he ended up prying her mouth open to get it out. But she did not growl or snap at Jason.
Keep doing things like you did with her bone, do it with her toys as well, as long as she doesn't begin to get aggressive about it, if she does, you'll have to find info on how to deal with it because it is a completely different situation than when she is fine about it. But I don't think she will. It sounds like you guys are a match made in heaven and you just mesh together very well, making training and pack position go very smoothly. Keep up the good work! 