I see this is a Worthington Fairy. I believe Colson either merged with, or bought out Worthington, but I'm not sure what year or what took place at the corporate level. There was some info on the tricyclefetish site about it, however that site seems to be down now. I'll throw a guess out there as to age. I'm thinking mid/late teens and purely by the tire style used. As these get older the tires tended to be smaller until you get to the steel wheel models of the later 1800s. I know Colson had taken over Worthington by the 1920s, so late teens would still be badged Worthington. Maybe some Colson experts on the CABE know when the company name for the Fairy models would have changed, so as to narrow the year down a bit more accurately.
As for value, I've seen these sell from anywhere between $300/400 to over $1000, depending on original condition. These trikes were designed for girls, so that they didn't have to straddle a bar which was considered an un-ladylike riding position at the time, even for girls of the age these were made for.
Dave