assessment when living overseas - some advice needed please

hi, i've just joined and looking for some common sense advice.  we live in portugal,.  my 5 year old daughter's been here since she was 9 months old, her pre-school say she has problems communicating and socialising at school.  they have arranged for assessment here in portugal in the new year with a panel of 'experts' at the hospital.  to cut a long story short, she's always been different and i think it might be autism spectrum.  she does a lot of delayed echolalia, repeating phrases from the tv etc, she can be very affectionate with me, and her little sister, but generally she is pretty distant and separate.   her writing, speech, socialising skills at school are not really there and she has trouble focusing on tasks.  she has never been good at keeping still.   she has never asked 'why?' her whole life.  she's very, very shy with new people.

i'm going to take an interpreter with me to the assessment so i dont miss anything in translation.  but my worry is, with the complication of assessing in two languages, things could be missed.   i guess i must flag up the echolalia etc but i'm also thinking 'what if she doesnt have autism and i get her mis-diagnosed'?.   is it possible or am i being daft?   i'd love to hear other peoples opinions.  sorry if i havent explained things very well.  just found out about the assessment last week and still trying to get my head round things.