Littlebella, you seem to be wanting a reasoned debate with your DD. BUT she pesists in bad behaviour. You should not HAVE to say - if you touch this book you will not go to the party, it was engh to say - DO NOT TOUCH THIS BOOK. She wilfully disobeyed a direct order.
I cannot understand those on this thread say 'ah she is only 6, saturday is a long time away' That child is clever enough to find the gaping hole in your argument and use it!!! She is certainly clever enough to know that on Saturday she is not going to the party because of what she did.
Her suggestion of taking one of her brother toys is also a clever answer.
TBH I would get tough, really tough. Once or twice is enough I can assure you. Seriously I only have to say to my kids 'DO NOT LIE TO ME. YOU KNOW WHAT WILL HAPPEN' to get tehtruth about things. Also I give MASSIVE praise when they do tell me the truth, even though they are afraid they will get in trouble (eg after breaking something by accident) They learnt very quickly that it is the LIE I hate, even more than the behaviour, not that the behaviour was acceptable in teh firstplace (they both had additional punishment for that)
IMHO the punishment needs to fit the crime, your DD has destroyed a present you were going to give, therefore no party. What is the point of no TV? Chores fine, but again she is not losing out by doing chores IYKWIM
IMHO I would say, 'OK you didn't realise THIS time you wouldn't go if you destroyed the book, but you do know for next time now, don't you'!!
I know I sound harsh and I have been lucky I have never had a wifully descructive child - like I said ONE OCCASSION Of damaging something of mine deliberately was enough!!! Of course they have accidents, but this was no accient, you put the book up high, you told her not to touch.
(as an side I also went mad when DH ate my chocolate reindeer at christmas!! I was saving it for desparate times, I hadn't even unwrapped it!' But he took it, unwrapped it and ate it!!. My kids were so upset with him as he had taken something of mummys without asking!!! He had to go out and buy me 2 BIG Lindt bunnies to make up for it!! - one of which is tempting him inthe fridge still )
You are the parent here, so what if the punishment is draconian, you are not exactly beating your child for a minor indescrtion, you are teaching her ina totally reasonable way that there are consequences to actions and she knows that she shouldn't HAVE to be told. Use the school analogy, if she had taken something of her friends/teachers without asking and then damaged it - what would she expect!!!