Is it permissible for my sister to write stories for children about the Tabi'in - such as Ibn Sirin - accompanied by cartoon drawings of them, given her fear of the impermissibility of drawing?

It is permissible to produce animated films that serve a predominant interest, with the exception of depicting Prophets, Companions, Imams, and those who possess sanctity. This is because representing and depicting them diminishes their status. This can be compensated by narrating the story through other characters without drawing the personalities themselves.