Au pair job

Hello everyone..this is the first time that i write in this forum
i write because i wonder if it is too hard to find a job as an au pair in Denmark...is it too demanding? i am also wondering why most of the families always ask for girls from the Phillipines, why is that? are they only the ones who are allowed to have that kind of job in there?
I am from Venezuela and i am 21 years old