Source: The Great Interpretation of Dreams (Ibn Sirin)
A laughing (smiling) mother in a dream indicates relief, mercy, and approaching goodness.
Source: Perfuming Humanity in the Expression of Dreams (Al-Nabulsi)
A laughing mother indicates the end of worries and good tidings.
Source: Signs in the Science of Expressions (Ibn Shaheen)
A laughing mother is interpreted as goodness and joy.