Osh Gosh Bgosh was a famous name brand clothing. Not sure if they sell that here. 

Despite 99Silva's less than detailed answer, there is actually some truth to what he says. Most parents in China would shun Chinese kids brands in favour of international brands. I know many parents who who buy all their kids' clothes and toys abroad. However, since that may not be a feasible option for you right now, I would suggest searching for goods that are important from abroad and sold on tmall. The best keywords to use are “代购” (brought in from abroad) or "欧美童装品牌代购" (kid fashion brands from Europe and US). Good luck!

Ask matty, It wears those sizes.

These are some of the top 10 kids clothes brands in China

1  巴拉巴拉

http://list.tmall.com/search_product.htm?spm=a220m.1000858.1000720.27.J4mTCE&cat=50023647&brand=45448&s=0&n=0&sort=s&style=g&search_condition=23&area_code=440300&from=sn__brand#J_crumbs

2 红黄蓝

http://list.tmall.com/search_product.htm?spm=a220m.1000858.1000720.107.J4mTCE&cat=50023647&brand=3625895&s=0&n=0&sort=s&style=g&search_condition=23&area_code=440300&from=sn__brand#J_crumbs

3 玛米玛卡

http://list.tmall.com/search_product.htm?spm=a220m.1000858.1000720.166.J4mTCE&cat=50023647&brand=8648708&s=0&n=0&sort=s&style=g&search_condition=23&area_code=440300&from=sn__brand#J_crumbs

4 派克兰帝

http://list.tmall.com//search_product.htm?q=%C5%C9%BF%CB%C0%BC%B5%DB+%CD%AF%D7%B0&type=p&style=&cat=all

5 彬彬

http://list.tmall.com/search_product.htm?spm=a220m.1000858.1000720.111.J4mTCE&cat=50023647&brand=10459716&s=0&n=0&sort=s&style=g&search_condition=23&area_code=440300&from=sn__brand#J_crumbs

6 小猪班纳

http://list.tmall.com/search_product.htm?spm=a220m.1000858.1000720.11.kcuxQ3&cat=50023647&brand=45441&s=0&n=60&sort=s&style=g&vmarket=0&area_code=440300&from=sn_1_brand-qp#J_crumbs

7 嗒嘀嗒

http://list.tmall.com//search_product.htm?q=%E0%AA%E0%D6%E0%AA+%CD%AF%D7%B0&type=p&style=&cat=all