Police in Chorley and Preston, both in Lancashire, posted pictures of the handwritten notes on Twitter.
Football officer Paul Elliott, who was on duty during Chorley’s match against Dagenham & Redbridge this weekend, was handed an envelope enclosing a letter written in purple felt tip pen.
Reflecting on the terror attack in London Bridge on Friday, PC Elliott wrote: “On duty today @chorleyfc v @Dag_RedFC whilst walking through town we were stopped by Eva and her Dad.
“After yesterdays incident in London this is another example of the good in people & a lovely gesture and feel very humbled. Thanks Eva & Dad.”
Addressed to emergency service workers, her note said: “You do alot of amazing things and work very hard! All I can say is Thank You!” from, Eva davies (age 9). P.S. enjoy the sweets.”
Her dad, Gary, replied to the tweet saying he and his daughter had gone around handing out the letters and treats over the weekend.
He wrote: “Eva had great fun wandering around Chorley and stopping for tea and cake as we handed these out to the emergency services we saw hope you enjoyed the sweets.”
Police in Chorley had the welcome surprise on Sunday when they returned to their vehicle to find a note from Eva as well.
In this letter, the young girl wrote: “Dear Emergency Service Worker, You do an outstanding job and you work extremely hard” – amusingly adding “mostly”.
Along with her letter she left Crunchie, Dairy Milk and Double Decker chocolate bars.
The officers posted the pictures with an appeal to find Eva to return the nice favour.
Chorley Police wrote: “Yesterday a little note was left on some of our vehicles which has brightened up our day! If anyone knows Eva, if you can get I’m touch I’m sure we can arrange something in return!”
Lancashire Police told Sky News they have been back in touch with Eva and her father and are looking to arrange for the young girl to spend time with their horse and dog units.