Question

Mother said to me," Did you sleep well yesterday'?l​

Answer 1

Tell her "I did".

Ask a different question as this does not specify what to do.

Answer 2

Answer:

Mother asked me if I slept well the day before .

Explanation:

Supposing that the sentence was to be changed from Direct to Indirect speech.

yesterday (direct) ----> the day before (indirect).

Thanks, have a great day ahead !!  ; )