Here are some quotes about cousin birthdays that you might like:

- "Cousins are friends that will love you forever." - Constance Richards
- "Cousins are those rare people who ask how we are and then wait to hear the answer." - Ed Cunningham
- "Cousins are many. Best friends are few. What a rare delight to find both in you." - Unknown
- "Cousins by blood - friends by choice." - Darlene Shaw
- "A cousin is a little bit of childhood that can never be lost." - Marion C. Garretty

I hope these quotes help you with your cousin's birthday! Let me know if there is anything else I can help you with.