Your family might still see the kid version of you. Show them the update; don’t wait for them to download it.

People update their picture of you slowly, and family slowest of all, because they hold the longest file. They are not being unfair on purpose, they simply have thousands of hours of an earlier version and comparatively few of this one. Waiting for them to notice on their own can take years.

Give them current material rather than arguing about the old picture. Tell them what you are working on, ask their opinion about something adult, let them see you handle a thing. It takes repetition, and it works better than any conversation about how they ought to see you differently.