Women are hard to understand, and women who don't have friends can be even more complicated. Below are a few points that can help you clarify why she's not that interested in having a social life, plus some clever suggestions on how to handle it:

She is a loner
Pro: If she is used to hanging out on her own, then it is unlikely that she will ever become dependent on you or even needy. Want to go out with the boys? No problem. Want a day on your own to watch sports in your pajamas? She won't care.

Con: If she spends much of her time on her own, she may have intimacy issues. This might not bother you at the beginning, when you are basking in the glory of endless nights out with your posse, but when it comes to finally making a commitment, she may be a little wearying.

She recently moved to your city
Pro: This is probably the least worrisome reason for her lack of friends, both because it is temporary and it has absolutely no bearing on her personality. It may even work in your favor: If she doesn't know too many people in the city, she'll have lots of time to spend with you.

Con: Until she meets new people to fill her needs and schedule, she may become dependent on you. For you, this will mean some hand-holding and emotional support until she finds the friends that she's looking for.

She doesn't get along with other girls

Pro: If she is more accustomed to communicating with guys than girls, she'll probably get along well with your buddies. So, you don't have to worry about inviting the guys over for pizza and the game, because she most likely won't mind hanging out with them.

Con: Unfortunately, when a girl doesn't mesh with other girls, it often means she has jealousy issues or a nasty streak. She may create unnecessary friction with other females in your entourage, such as your female relatives, coworkers or friends. And these constant clashes will undoubtedly create tension between the two of you.

She lost touch with her friends because she devoted all her time to past boyfriends
Pro: While this reason might scare you off initially, it's not a completely bad deal for you. History tends to repeat itself, so you are pretty much guaranteed a devoted girlfriend from start to finish.

Con: A supremely devoted girlfriend will probably expect the same from you. She may want you to make all your plans together or tag along on all your outings. And the worst possible outcome would be if you started to lose your friends because of the sheer amount of time you are spending with her.

She is a workaholic
Pro: With an independent, career-minded woman, you are guaranteed to have your free time, regardless of whether she has an ample social life or not. She is too busy chasing after her promotion to keep tabs on you and what you are doing while waiting for her to leave the office. An added bonus is that you'll probably never have to worry about her becoming dependent -- financially or otherwise -- on you.

Con: While you won't have to compete with her friends for her attention and free time, you will have to fight it out with her boss and career goals, and, in the long run, she may not make enough time for you.