He said, "how 's your mother?".
Answers
Indirect/Reported Speech refers to a dialogue being told to a third person/reporting what happened to a third person.
Example: Aidan said,"I'm feeling nauseous." (Direct)
Aidan said that he was feeling nauseous. (Indirect)
In the above example, when writing in indirect/reported form, the sentence changes according to its tense. Also, modifications regarding certain words like 'this' changes to 'that', 'tomorrow' changes to 'the next day', 'will' changes to 'would', 'can' changes to 'could' and many other words have to be made. Also, if the sentence is contains an interrogation, then 'said' changes to 'asked'. Punctuation marks other than a full stop (.) cannot be used in indirect/reported speech.
He said,"How's your mother?" (Direct)
He asked how his mother was. (Indirect)
He asked how his mother was .
DETAILS :
The reported speech must be noted .
The reported speech is the word used before narration.
This case the reported speech is "said" which is past tense.
Hence the indirect sentence will also be in the past tense.
The meaning should not change.
And also the question mark is removed.
The word "asked" has been added instead.