K.H.
My oldest daughter had the same problem when she was also 6. I waited quite some time and her baby teeth never got loose. I took her to the dentist and had them pulled. I don't know if we would have waited longer if they would have come out on their own, but even waiting as long as we did caused her front teeth to be crooked. I've actually had to have a lot of her teeth pulled because for some reason they don't come in where they are supposed to so the baby ones don't get loose by themselves. Good luck! Hope the this helps a little.
K. H.