So-called - Tradução em português

Help with this expression... in the CALD they say "used to show that you think a wprd that is used tp describe someone or something is not suitable or not correct"

The text says " It was suspected that a so-called family friend had done something to her when she was three "

Consegui captar a idéia... mas ainda não sei como empregar essa expressão em outras situações... quem quiser ajudar... agradeço.