A naughty child and feelings of guilt

Ok, so I have a problem. I have a naughty child. Of course she's totally gorgeous and wonderful and sometimes her naughtiness actually makes me laugh, but she is nonetheless, naughty. Now I know some parents wouldn't dream of using the word naughty for fear of labelling their child or giving negative association, but I try not to be too pc about it all. For me, naughty just means they don't do what they are told. And if that's the case, then my little Edie is most certainly very very naughty. So much so that it's beginning to drive me crazy. I have no memories of Renée being naughty in the same way and I'm sure I haven't blanked out the memories of her being naughty. I just don't think she was. So how can two children, of the same sex, from the same parents, with exactly the same upbringing, be so different? Is it something to do with being a second child? Are they constantly in the shadow of their older sibling so they are forever seeking attention?

I'll give you an example of Edie's naughtiness. Last night, just before bedtime, Edie pulled Renée's hair. She didn't just pull it a little bit, but she gave it a good old yank. And this was without any provocation at all. Edie just marched up to her and decided to pull her hair. It was as simple as that. Now if it had been the first time she had done it then I would have told her off, made her apologise, explained to her why she shouldn't do it, etc etc. But this wasn't the first time she had done it, or the second, or even the third. I haven't been counting, so who knows how many times she has done it, but it has been quite a few. I have tried the good old 'naughty step' and although it has always worked amazingly well for Renée, Edie just won't take it seriously. She laughs when she's made to sit there, constantly gets off and runs away from it and even politely requests to be sent there as if it's a treat. So by the time she had pulled Renée's hair for, let's say the 20th time, I was starting to think about taking drastic action.

Edie has always been, not only a hair puller, but a biter as well. And in the past, when I've been searching for ways to stop her from biting, I have come accross tales of mothers biting their children back. Apparently it causes the child so much shock (and probably pain as well) that it makes them realise just how horrible it is to be bitten and so they never do it again. Although I couldn't quite bring myself to bite Edie, I thought maybe this was the time to employ similar tactics with the hair-pulling problem. So, against my better judgement, I decided to pull Edie's hair. I have to say, her reaction was quite heart-breaking. She looked at me, her bottom lip started to quiver and she burst into tears. I think she was in total shock that the person who she always turns to for love and comfort was the instigator of her pain. She didn't know what to do. Instead of coming to me with her arms up wanting a kiss and a cuddle, as she normall would have done, she ran to the corner of the room and stayed there sucking her thumb. I found that, not only did I want to turn back the clock and not pull her hair, but I wanted to scoop her up and my arms and comfort her until she stopped crying. The resistance brought tears to my eyes. Literally. But I had to stay strong. I went over to her and said 'Edie, Mummy is really sorry to have hurt you. Pulling hair is wrong. But now you understand that pulling hair hurts. When you pull Renée's hair you hurt her. And this makes Renée sad. Mummy says sorry for pulling your hair. I won't do it again. Please say sorry to Renée for pulling her hair and tell her you won't do it again.' So she went over, apologised to her sister and we all had a big cuddle. I felt vindicated. Maybe you need a little pain to have any sort of gain at all.

Ten minutes later, Edie pulled Renée's hair again. So this is why I am writing this post. I need help. How do I stop Edie from being so naughty? I know she loves her sister and I have never felt any resentment or jealousy from either of them. Edie follows Renée around everywhere and wants to do exactly what her sister is doing, and Renée likes the role of big sister and relishes teaching her all the things she knows. When friends come round to play they sometimes prefer to play together even though they see each other every day. So I really don't think there is sibling rivalry. I am hoping that this is a phase and that she will grow out of it very, very soon, but in the meantime, can somebody please help me out??!!