I'm posting a link to info about TSS (toxic shock syndrome). To my knowledge this is the only potential problem. If she didn't get this then she will be fine without doing anything other than removing the tampon. The vagina will clean itself out though it's own processes, although a douche may speed up the process. I had something similar happen with a sponge years ago. It was very smelly, but most of the odor went with the sponge itself and it cleared up very fast once I got it out.