[Wanted Melbourne] Kids overnight pack for 8yo

I'm planning to take my 8yo niece on her first overnighter at some stage over the summer, so I'm trying to assemble some gear for her. If anyone here has an unwanted kids size pack that will enable her to carry sleeping bag, clothes etc, please let me know! She's a tall and skinny 8 kid for 8 years old.
Cheers.
Cheers.