Editing/Adding to JSON file

I have a Google Map with some markers on it. It pulls in the marker information from a JSON file. Is there a way of adding extra markers to the JSON file via wordpress? (so the client/end user can easily add their own)

Example JSON for Marker:

{"id":"4","name":"A house","lat":"44.983935","lng":"-93.380542","address":"515 Winnetka Ave. N","address2":"","city":"Golden Valley"}

I have searched for plugins, but I don’t really know enough to understand if they are what I need. Apologies if this is in the wrong section.

Thanks