Meet Eva - she's nine and the emergency services love her to bits!
And there's a pretty cool reason why.
Eva who's from Lancashire wrote 12 different letters to NHS and police staff and left them on parked vehicles.
She also left them a bar of chocolate to let them know she thought they were "awesome".
It all comes after Eva watched a YouTube clip of NHS staff and police officers doing their job.
The envelopes were addressed to "Emergency Service Worker" and placed on the window screen of police vans and ambulance vehicles.
One read: "You're awesome, my friends think you're awesome, enjoy the chocolate."
She also thanked police in Lancashire for doing an "outstanding job" and working "extremely hard".
Chorley Police put a photo of the note on their social media account and said the surprise "brightened" their day.
You're awesome, my friends think you're awesome, enjoy the chocolate
Her Dad, Gary, said: "The police dropped me an email last night and said they'd like for her to come in and have a look around. They said they'd maybe try and make some time to go and see the police dogs and the mounted police, which she'd love."
Well done, Eva!