I'm really concentrating on positive attention ! Because of the same thing ! Dcg who is 2 is immune to time out but lives to 'help ' and just beams when I thank her !! I give her a wet one and she spends most of her free play time 'cleaning ' . She doesn't play well with the other kids and steps in to aggravate them more than join play ( we are working on this )
One is pretty young and I think your right , she's picking up her sisters behaviour !!!
Sounds like your handling her behaviour the right way !!!