Bird isn't looking brillint

My female cockatiel has a male friend living with her at the moment and both seem very happy, he's lively and talkative and so is Molly, but every so often I notice that Molly is breathing heavily and is wheezing and panting. She also, always seems to have red eyes just in the corner of them, not around them but as if they were blood shot. Also her beak is getting very long, suggesting either an illness or lack of foraging and eating, and finally I noticed today when she started panting that her tail drops and her wings rise slightly. Other than this she is whistling, running around the cage and is very lively but she seems to have her very off days. Can someone please help?