I tend to think of child-like as more positive than childish.....childish being the part where I am acting like an immature, selfish, whiny, defiant, brat (all the negative things there can be about children, I suppose). But child-like I think of more as humility, sincerity and innocence, trusting without question, understanding I can't do something and someone else who does can help me and being willing to ask for the help without fear, simple faith in someone......positive qualities of children. Spiritually, it's better to be child-like than childish, I think.
I guess being child-like does not always mean that you are actually acting like a child, or being childish! I would rather hear someone tell me I was child-like than childish.....I don't think acting child-like means that you are actually also childish, as in bratty! It might be mean that you do have a dependent sort of a nature though, like a child might.....because that's your way of asking for help when you need help.
Just my opinions, and hope they're helpful in some way!