Oh pls dont apply the 'qing cao you' on her butt!!! it not only wont helps on her nappy rashes and will worsen it!! and this is not even suitable for babies!! do you have Desitin at hm? apply a THICK layer on her butt on every nappy change. If her rashes is very bad, it might takes sometimes to recover. That time dear son also, took about 2 days for the pain to goes off and around 2 weeks for the 'scars' to lighten..
And, teething will NOT cause diarrhoea. I only heard before it will cause watery stools, but not diarrhoea. Diarrhoea is super watery stool, more than 5x per day. If still persist, I think better bring her back to the pediatrician or hospital in case of dehydration.