Casting actors

I have cast a young couple, Gill and Kegan to be in my film. They are already a couple so the romantic scenes will be more believeable. For the older couple I have cast Jean and Terry, who have been married for 50 years. Gill is slim with long brown hair and looks similar to Jean and Kegan is tall with brown hair and looks similar to Terry, which will support the storyline that Gill and Kegan are Jean and Terry as a young couple. No one will be required to speak so matching acents or dialogue won't be an issue.