I know exactly what you are going through.. I used to work and do IM at the same time but that was way too hectic for me. By the time I got home, I was way too tired to do anything let alone even give my husband attention. Good thing he has his PS3 games to distract him =)
Right now, I work full time in IM plus do some projects for myself.. On the other hand, my husband is the one who is working 10 hours a day and comes home very tired so I know what he feels like. I don't have any girlfriends either so I can see why she feels lonely.
What I do recommend though is taking a day out of the weekend for you both to spend together. Otherwise, try to get her to make some friends by doing extra activities maybe like volunteering and stuff. As for yourself, it seems like you are working way too much. You might want to cut down on your hours if your job permits and this way the both of you won't be as stressed, allowing you both to see more of each other.