"Her house is in America."
Translation:उसका घर अमेरिका में है।
The ending of the possessive pronoun agrees with the object, not the owner. So:
उसकी बिल्ली उसका कुत्ता उसके कुत्ते उसकी बिल्लियाँ
His cat OR Her cat His dog OR Her dog His dogs OR Her dogs His cats OR Her cats
i think because in this example "her house" is a concrete thing, the subject of the sentence, and "America" is the object. the "gar" being later in the sentence would make that the object of the sentence, more like "she is in the American house".