My oldest has just turned 15 and she is such a great help (except when she is having a hormonal teenage day!) She could run this house by herself lol. We have just moved house and decided that in this house everyone will have their own area of responsibility. DD#1 has the kitchen and her room and the bins, DD#2 has her room and the bathroom (basic cleaning only!! she was very excited because I bought her a pink sponge to wipe the sink with) Dh has yard and lounge room and I have everything else. This is a huge step for DH cause he usually does nothing! despite coming from a very enlightened home where his dad did all the washing and ironing.
DD#2 who is nearly 7 is quite helpful when the mood takes her (she is VERY lazy!!) and also feeds her fish which she likes doing.