Alternative translations of ‘狗长尾巴尖儿’ et al
气的我只要给平儿打报不平儿。


Angered me to the point of desperately wanting to file a grievance on behalf of little Peng.


  忖夺了半日，


Carefully deliberated half a day


  好容易‘狗长尾巴尖儿’的好日子，


It is a long awaited day of celebration for (someone's) birthday, 

I didn't read the novel, so I don't know whose birthday it was


  又怕老太太心里不受用，


so I'm afraid the old madam might feel displeased,


  因此没来，究竟气还未平。


therefore I didn't come forward, however, my anger has not been subsided.