This simply means a beautiful young singlelady with a fair or light skin. But since now-a-days that seems to be a racist insinuation the meaning shifted to simply imply a lady with good characteristic and qualities.
Fair Maiden. From an old folksong.."...never fades the glory hark the fair maiden humming the story of love..."
12 step recovery jargon referring to someone new who talks about how great life is, now that they'resober. Usually meaning that the person is out of touch with reality.
The new guy seems pretty happy for a dude who has no job, no money and no family. He must be on a pink cloud.