Answer:
"Ageist"
Explanation:
According to my research and based on the information given in the question about the behavior that Billie is showing, I can say that Billie is an "Ageist". This term is defined as a person that shows stereotyping or discrimination against individuals or groups based on their age or age-range. This term was created in 1969 by Physician Robert Neil Butler.
I hope this answered your question. If you have any more questions feel free to ask away at Brainly.