The "S" word

We've entered a difficult stage my friends. Dealing with that "S" word! Yup, I said it. SHARING. Now that Kyla is officially mobile, she wants to get into everything Kinsleigh is doing. And I don't know how to help alleviate some of the stress of this situation. I feel like I am constantly nagging to share. But sharing is such a very hard concept to learn and it doesn't really get fully understood until much later in life. So I'm in a pickle. You don't get training in this kind of stuff in "Multiple Children 101." There is part of me that is so frustrated because Kinsleigh tells Kyla"no" constantly and rips everything out of her hands but then another part of me that says, "Word girl! You do need some of your own space!" Kyla is a little magnet. And that can be annoying to me even, so I totally can see where the three year old frustration is coming from. But at the same time, sweet Kyla just wants to be a part of her sisters world. And Kinsleigh absolutley adores her but just like all siblings, not ALL the time. So I ask you others of multiple children...what methods work best for your family? I want to teach the idea of sharing but don't want to feel like I'm constantly shoving it down her throat. Trying to distract Kyla with something else, say another toy, doesn't work either because she only wants to be doing what Kinsleigh is doing and will switch activities the moment she does. I need advice because the "mommy voice" is hurtin!