My issue is how much to push with these kinds of things?
IMHO that depends hugely on temperament. Mine does best with huge amounts of coddling and praise, and a good incentive structure. Any amount of parental pushing results in misery all around. And I suspect mine is at least somewhat temperamentally like yours - when mine was 4.5, I finally asked her when she was going to stop calling for me to help her on the toilet, and she suggested "maybe when I'm 6." (I think it was not quite that long. But nearly.)
IMHO, a 4.5yo who can read chapter books (even Rainbow Fairies) when she chooses and can manage to tie her own shoes after two attempts when she chooses is not a kid who shies away from a challenge. She just chooses her own challenges, and has figured out how to get her needs met in other areas with maximal efficiency, by getting someone else to do them for her.
In our house, "it's too hard" nearly never means that. It usually means "I don't want to do it, nor do I want to argue with you over doing it."
