Can I you describe the pink you are seeing s little better? Does it look like flecks of blood or is her fur pink? When s momma has joeys shoving their heads in and out of there to nurse all the time, it's very common for the edges of the pouch to turn out a little bit as it gets stretched around. The inside if her pouch is mucous membrane and should look a nice healthy pink color (like the inside of your nose or mouth). If it looks red or angry and inflamed and certainly if you see any bleeding, then vet ASAP. Most of the time when they get a pouch infection, you will see ichy, discolored (yellow, purulent, smelly, and just all around ick).