The Broad Index is a trade-weighted index used by the Federal Reserve to measure the performance of the US Dollar against a basket of 16 currencies. The central bank created the index as it was viewed that weighting in DXY overemphasized the Euro. The index is not traded, and thus does not carry a ticker symbol.
Yes, her can be an adjective if it is acting as a possessive pronoun. For example, She gave me her coat. Her is describing who's coat it is.
At its base level, an Adjective Phrase is a PREPOSITIONAL phrase that is functioning as an adjective in the sentence and modifies a noun or pronoun. It answers the questions which kind or which one. ALL Adjective Phrases will begin with a preposition.