As a Freelance Production Artist, are clients entitled to native files? My now ex-client gave me images to edit for their website and marketing g and are now requesting all the PSD's so they can have for further editing.
It depends on what you agreed on before starting and what is written in the contract (you do have a contract/work order with a detailed deliverable list, don't you? - well, next time you will).
Usually the source files cost extra.
In the future always have a detailed, agreed on and signed list of everything that has to be delivered, also, you should tell them explicitly the source files cost extra before signing the contract so there are no surprises later.
For this client you can either insist they pay extra or just give them the files and write it off as a learning experience.