Whereabouts are you Haggis ? roughly ?
I have a seasoned hazel rod, some willow ones that were cut seven months ago, and I think there's an apple one in the shed too.
Blackthorn makes a really good stick, but it's inclined to be heavy-ish.
I know where there's hazel growing that has honeysuckle growing around it tightly enough that it's forming twisted 'magical' staffs Just three or four twists up the length. If you're in the west side of the central belt you could go and cut one for your daughter.
We used to do that on purpose years ago, wrap the Hazel and Chestnut stems with Old Mans Beard, a type of Clematis. The other thing, to make a true thumb stick and not just a fork, was to remove the leading bud and stem back to the fork a few inches below on Ash and Chesnut saplings and leave them to grow a natural “U” shape rather than an uncomfortable “V”.
6 yr olds Gandalf Staff needs to be fairly light wood. The recommendations of Willow and Hazel are good. chestnut is light and strong, most of our sticks were 3yr old Chestnut cut for the NHS walking sticks.