im not sure if this is an age thing

seems lately everything i ask sofia (3yrs) to do get a "no" in a realy stroppy mannor

it seems she's very aware that she is able to wind me and DH up, and does it on a very regular basis, also being really rude.
i also get fed up with her when she constantly snatches things away from bindi, even bindi's own things! and she has adopted this horrible screeching tone to her voice , screeching "no you cant have that!" and "no you cant feed bindi" at me. and "no you cant sit there" at anyone.... example, my friends bub was sitting on the floor playing with our ergo, sofia noticed and strutted over snatched it away and said no you cant have that!.....you get the message.
a friend suggested that maybe she feels she needs to have some control, i do give her plenty of choices, but not too many these days as that was causing problems
now im pretty sure someones going to tell me thats 3yr old behaviour!! or maybe not

but my question is what can i do here?
im feeling a little stretched-with them both being sick recently and being more demanding, so im not handling things too well

i dont think this attitude does not warrant the taking of toys, and currently im saying, thats rude... i dont like you talking like that...its ok for bindi to have xyz you concentrate on what you doing i'll parent bindi thankyou... and me getting totally annoyed when she screeches at me for breastfeeding, but ive tried saying bindi is hungry i need to feed her like i feed you when your hungry..yadda yadda.... doesnt seem to be working- do i just put up with this? or does anyone have any coping stratagies? tia
