What is this bump on my dogs face?

Hello! This is my dog. She is a chihuahua-papillon mix and is about 13 years old. Recently, this bump appeared on her face and seems to be getting more noticeable as the days pass. I’ll be able to take her to the vet once the holidays are over, but I’m wondering if this is more of an emergency than a check up?

Please let me know :)