To express gratitude to a girl, you can say:
1. Thank you for your kindness.
2. I'm really grateful for your help.
3. I appreciate everything you've done for me.
4. I can't thank you enough for your support.
5. I'm so thankful for your friendship.
6. You have my deepest gratitude.
7. I wanted to express my heartfelt thanks to you.
8. I'm truly thankful for having you in my life.
9. Thank you for being so amazing.
10. Your kindness means a lot to me.
Remember to be sincere and genuine when expressing your gratitude.