|English Grammar Intro to Phrase and Clause||Independent Clause|
Independent Clauses itself expresses the complete meaning.
In this example, the two words she (subject) and giggled (Verb) gives the complete meaning that the girl laughed softly and repetitively in a silly manner. This is an example, of independent clause because the clause itself makes the complete sense.
Here the part of the sentence-“I am feeling thirsty” is an independent clause because itself has a complete meaning. It itself implies that the subject is thirsty and wants water.