* "A sharp tongue": This idiom means someone is quick to speak harshly or critically. It refers to a person's tendency to be sarcastic or cutting in their words.
* "A tongue like a whip": This idiom also signifies someone who speaks sharply and harshly, often with a stinging effect on the listener. It emphasizes the quick, forceful, and hurtful nature of their words.
* "A viper's tongue": This idiom describes someone who speaks maliciously and deceptively. It draws a comparison to the venomous nature of a viper, implying that their words are harmful and intended to inflict pain.
It's possible that "acid tongue in her head" is a colloquial expression specific to a particular region or social group. However, it's not recognized as a standard idiom within the broader English language.