Ms James, 53, was found dead in Akholt Wood close to her home in Snowdown, Kent on April 27.
Police formed a guard of honour near where the officer had lived as her family said their final goodbyes.
People were asked to wear blue in a nod to Ms James’ career at the Kent Police.
There was a procession through the village of Aylesham where the officer had lived.
At the funeral, her son Patrick Davis paid tribute to his mother as “the most amazing woman” with the “most infectious laugh”.
Patrick, 23, added: “Mum was the most amazing woman, who would go to the end of the earth to help anyone.
“She had the most infectious laugh and a huge heart and I am so pleased I had the pleasure of calling you my mother.
“Mum would light up a room with her smile as soon as she walked in. As she entered she would glow with positivity, love and warmth.
“I miss you more and more every day mum but I know you are always near. I love you mum. Goodbye for now but not forever.”
Ms James’ daughter urged the community to “come together once more” in a Facebook post.
Her daughter Bethan Coles said on Facebook: “It would be lovely to see the community come together once more; so if you wish to gather in the Market Square or line the streets for a final farewell please do so!
“There will be a small private wake however the Ratling will be open for those wishing to have a drink in my Mum’s memory and have kindly offered to open early and show the service on their big screen should anyone wish to see it.”
Callum Wheeler, 21, from Aylesham, has been charged with Ms James’s murder.
A trial date has been set for November 29.