I did the JMT this past summer. I second the idea of having them start with you (if they don’t want to start in the Valley, they could meet you up at Tuolumne) - and then hiked with you until Red’s Meadow. From Red’s, they can easily get a shuttle to Mammoth, and then bus/train back to Yosemite. Plus, this is a spectacular part of trail…Lyell Canyon is super pretty and chill for a first day, and then going over Donohue Pass to Thousand Island Lake, and all of the gem-named lakes is just stunning…you can all celebrate with burgers when you get to Red’s.
Otherwise, I guess they could meet you at Red’s and you could do the section from Red’s to Vermillion Valley Resort (you gotta spend a day here). VVR offers transportation to Edison Lake, at which point civilization can (somehow) be reached…though it’s probably best to have a car parked there. This is an OK section of trail…Lake Virginia is really nice, and Silver Pass is nice, but it’s not the prettiest stretch.
Finally, you could have them meet you at VVR, and hike to Muir Trail Ranch and then catch the ferry out across Florence Lake. This is a nice stretch…Seldon Pass and Marie Lakes are stunning. OR meet up at Muir Trail Ranch (and have them bring your re-supply! because MTR charges a fortune) and hike through Evolution Basin, over Muir Pass and into Le Comte Canyon, where they can then exit out over Bishop Pass. I’ve never hiked Bishop pass myself, but I’ve heard it’s pretty steep. Evolution Basin, Muir Pass, and Le Comte will definitely be memorable, though it is harder to figure out the logistics of getting back to one’s car.
sophia