My 7 year old daughter has the same problem. She had it a while back with her bottom two front teeth and now it's happening with her top teeth. We took her to the dentist when we noticed it on her bottom teeth. He said if they didn't come out within a few weeks on their own, to bring her back in and they would pull the baby teeth. That was because they were making the permanent teeth come in crooked. The baby teeth on the bottom did finally come out on their own and the permanent teeth have pretty much finished coming in straight.
Now it's happening on the top teeth as well. The two permanent teeth are very visible and up until a couple of weeks ago, she looked like Tow-Mater from the movie Cars with these two front baby teeth sticking out at an angle since the permanent teeth behind them were pushing them forward. One of the two baby teeth fell out 2 days before we got her to the dentist. But the other one is still hanging on. The dentist said the permanent teeth were coming in straight, and that unless she still had that baby tooth in the next 2 months, just to let it come out by itself. We have to remind her to wiggle it all the time, but I'm sure it will eventually come out.
Reading these responses, I'm shocked at how common this is. I remember my mother-in-law telling me stories about my husband's teeth when he was young. His were weird in that they all came in at the same time. She said he looked like a shark because he had two rows of teeth on the top and bottom. They had to pull his baby teeth since they were all coming in at the same time and he needed the room. So when I saw it happening to my daughter on her bottom teeth, I was so worried the same thing would happen to her. Fortunately, it's not as bad for her as it was for him. But she still looks funny with that one front tooth sticking out. She's a beautiful little girl, but when she imitates Tow-Mater, saying his lines in his perfect hillbilly accent, you can't help but laugh histerically. Good luck!