What can i do for a young dog when she is in her first heat she is in the 3 stage?

During a young dog's first heat, especially in the third stage, it's important to keep her calm and comfortable. Provide a quiet and safe space for her to rest, and consider using doggy diapers to manage any discharge and keep your home clean. Maintain her regular routine but avoid strenuous exercise and interactions with unneutered males. Monitor her behavior for any signs of distress, and consult your veterinarian if you have concerns.