The rule not to end sentences with prepositions is rather hotly argued among nerdy grammarians, with some saying that it's a complete myth.
However, I completely agree with you that "where is she" is a much better translation. "where is she at" is so jarring to me that it's what brought me into this discussion. It's becoming more accepted in native speech, but it's still... off.
"Where is she?" = "أين هي؟"
i treat it as a rule with legitimate exceptions, which is true of so many grammar rules. but for me an exception either needs to be ubiquitous or the alternative archaic and/or untenable. so where are you from. that is the best example illustrating my approach. it is ubiquitous. and the alternative is archaic: from where do you come? i come from a land of grammar. ;)