Over here in Portugal the kid would just have to clean is arm and i'm sure the mother would be spoken to. Also, the exibition of religious symbols is proihibited, you cannot wear crosses on the outside or your head covered as in muslim cultures, being atheist i don't really give a c**p to what ppl put in there heads or necks.
In this case the mother most probably suffers from brainwashe desease and really as no clear idea of what the swastika means in modern society, wonce a simbol of peace and serenity it now has become a symbol of evil and racism.
"Religious belief is the “path of least resistance”, says Boyer, while disbelief requires effort."