DD1 turned three in November (2.5 months premature). After a few gentle attempts, we tackled potty training properly last May. She was dry within a couple of weeks and the accidents she's had since then you can count with one hand (and some of those occured shortly after arrival of dd2). But pooing is a whole different story! Every now and again she has done one on the potty or toilet, but almost all of them end up in her knickers :( At some point we started a sticker chart and the success rate went up very quickly, but even though she raved about the stickers themselves and also the present she got after three stickers, novelty wore off after the first few presents and she did more and more of them in her knickers again. She's definitely aware of when she is about to go, I think she just can't be bothered and doesn't want to interrupt what she's doing! I'm starting to get quite annoyed and am starting to wonder if the "never mind, next time tell me beforehand" approach is not appropriate any more 
I have just started saying to her we might have to put her back in nappies if she keeps pooing in her knickers and she doesn't want that. Of course, neither do I, so it's an empty threat which isn't my style at all normally :(
Any advice? What would you do? It's been over seven months...