What now? She's 27 years old, I'm on my 240th generation at the moment and don't want to start over, and she hasn't gotten a single marriage proposal. I aodpted her when she was 23 years old. She has no adopted children so I'm confused. Is this the end of this line? Am I going to have to start over? Please, can someone help me? She's getting older as I wait. Thanks.

240th generation? That's some dedication. If you're already that far in, I doubt this would be the problem, but what version are you playing? In one version, there was a glitch that when you got to have a lot of generations it would get all glitchy and you wouldn't be able to continue - but that happened around the 30th generation, so I don't think that would be the problem here.
You haven't gotten a single marriage proposal in this generation, ever? Not a single one? That sounds like a glitch to me, if you really haven't gotten a single one yet. I can't really help you there. You'll have to wait for someone who knows more about the game than me for that. -_-
My suggestion for now would be to back up the game now (look here if you don't know how, assuming you're using Windows: http://www.ldw.com/faq.php?game=10&platform=9&f=82&q=908#answer) and if she dies without getting an adoption event or a marriage proposal, you can restore it and keep on going.

It could also be a result of the following, which applies to all devices and computers.

You should first check to make sure that your game is not paused; however, this problem is most frequently caused when people try to make the game progress more quickly by adjusting their device's system clock. While that sort of "time travel" is a popular way to speed up game play, real-time games rely on the accuracy of the computer's system clock to operate properly. Unpredictable results can occur if adjustments are made to the clock, especially moving the clock backwards in time. Different games will respond differently under those circumstances, ranging from minor statistics anomalies to killing whatever is living in the game. Virtual Villagers 1: A New Home has a much more complex real-time engine than some of our other games, and you're much more likely to see problems with it when adjusting the system clock.

While many people do adjust their system clocks to speed up play, doing so affects far more than just the games. Every application in your device is affected, including the file system and other system applications. For all of those reasons, we do not recommend changing your device's clock to speed up game play.

There are a couple of ways to resolve the problem: You could wait it out and see if the game recovers or you could delete the malfunctioning game and start over.

I know starting over is not something you would want to do. You may also find it handy to look into backup methods for your specific device or computer (if you can't use the Windows link above).

Moonstone Wolf, I would make a back up of this game right now and keep reloading it until you get a proposal. Everytime you load the backup copy she will still be 27 and get another chance at a proposal. Maybe after reloading it and letting her age a few days, then going back and restarting her at 27 the qlitch or whatever it is will go away. Don't let her age another day without a backup to reload.