Bring broth to a boil with the 1/2 cup of chicken then add the pasta. Cook on medium heat until the pasta is done to your toddler’s preference.
In medium saucepan over medium heat, mix milk and cheeses, stirring continuously until cheese has melted. Add in pumpkin and blend. Mixture should be smooth. Meanwhile cook pasta following package directions PLUS 3-4 extra minutes, until pasta is very soft. Drain pasta. Add pasta to cheese sauce and stir until pasta is well coated. Use masher to mash Mac & Cheese to smoother consistency, if needed.