Your answer would be that the subject of the sentence is "Ira".
Explanation:
The subject of the sentence above is the NP "Ira". A sentence is made up of two parts: the subject and the predicate. The subject includes the noun that is performing the action described in the predicate. In order to identify the subject of the sentence, you should ask the following question: who verb(ed)? That is, who loves to read books in summer? The answer to that question is the subject, the NP "Ira", while the VP "loves to read books in summer" is the predicate. The predicate is everything that is not the subject.
The abbreviations after a word in the dictionary tell you the word's: part of speech.
Explanation: