Hi, I am Shao Ren, I see you need someone who knows Chinese to help you take a look at some translations. I'm up for the task if you'll have me. Here are the things I can offer:
1) I'm Malaysian, that may not mean much, but I've been learning, speaking and communicating in both Chinese and English since I was born. I've even taught a class of 9 year olds Chinese in a government school before during my college break! I'm fluent in both the languages, and can definitely guarantee that I know the ins and outs of both languages. I can definitely tell if anything sounds unnatural to usual speakers, and whether or not it is suitable for the target age group.
2) Having spoken both English and Chinese for such a long time, I do not use machine translation. I use English (at work as tech support) and Chinese (when hanging out with friends and family) on a daily basis, thus I can guarantee the accuracy of my work. I have done prior translation work for cosmetic companies and vacation sites, so I'm familiar with the use of more natural tones of wording.
3) I am a songwriter and arranger, this means I deal with needing to pick between multiple subjective choices almost daily. While I can never guarantee that I am picking the objectively best choice, I will do my best to give you my honest opinions of each version.
I hope that we can get the chance to work together. If anything I said feels that it could help, feel free to let me know! Here's wishing you a great day.