Holly is one of those literary characters that academic folks love to talk about since she isn't as cut and dried as she initially appears. She might first seem like a party girl with no substance, who cares only about money and about finding the next fun thing, but if we spend a little time with her we see that there's a lot more there.
Holly was orphaned at a young age and we learn that her childhood was pretty rough since she was forced to move in with some pretty terrible relatives after her parents' deaths. She and her brother Fred eventually run away and they end up living at Doc Golightly's after one of his daughters finds them trying to steal milk. The two look so pitiful that Doc takes them in, and Holly eventually marries him because he's been so good to her and because, as she tells us, she loves him. And at some point it becomes clear that Holly develops real affection for the narrator. She also seems to care a good deal about Sally Tomato (even though he's paying her to hang out with him). So it's obvious that she does have emotional depth.
And we can't forget about her attachment to her brother Fred and her reaction when she finds out that he's been killed in action. Holly's rare but meaningful revelations about her brother show us that there was a happier period in her life, a time when she had her brother near to keep her warm. And they also show us that Holly's painful past is never far from her thoughts – Fred seems to be the one shining light in her otherwise difficult childhood, and memories of him probably also bring with them recollections of the less happy times he helped her deal with. Fred's absence while he's at war lets us know that Holly really has no one she completely trusts or feels comfortable around since Fred was always the one to provide that for her:
"Like my brother Fred. We used to sleep four in a bed, and he was the only one that ever let me hug him on a cold night." (3.7)
When Holly asks the narrator if she can call him Fred since he reminds her of her brother, we see that perhaps she's trying to recapture that safe and warm feeling she had with her brother.
So, what are we supposed to make of Holly Golightly? It's true that there's a lot for us to not like about her. She steals Mag's fiancée, she doesn't seem to care who she inconveniences in order to get what she wants or needs, most of her personal relationships seem fleeting and meaningless, and she never settles down the way we hope she might. Plus, although she does seem to develop genuine affection for the narrator, and although this relationship appears to matter to her, even that one is ultimately short-lived, too.
But there's also a lot to really like about Holly, and we might even feel sympathetic for her when we learn how she's ended up in New York fending for herself. Holly forces us as readers to question notions of who the good guy is and who the bad guy is. Are we supposed to like her? To despise her? To hope for a happy ending? To think that one day she has to pay for her carelessness? She doesn't make it easy for us to answer these questions, but we think this is what makes her such an interesting character. Holly's a bit of a challenge, and we have to appreciate her for that.