As-salāmu ‘alaykum wa raḥmatullāhi wa barakātuh, My little sister is following a few lessons about Tawheed but she is taking notes but it seems like she isn’t taking is seriously and she keeps laughing what advice can you give her.

Ustadh AbdulAziz al-Haqqan

Let her continue and don't bother her, as it might be because of you as a sibling, just encourage her or if she doesn't need encouragement and she is watching on her own let her have her space.