Emma is quite an anomaly for her time; her glasses -- something a person of her station would never have afforded -- is symbolic of her character traits as well. She can read, is educated somewhat, is reserved and even naturally refined, though this is often misread as "quiet" or "shy". She is shy as well however, and speaks little of herself or indeed at all.
Orphaned, she started life on her own as a flower girl -- someone who sells flowers that they could find underfoot near the flower seller's stalls. No living was remotely possible on what even a successful flower girl could make and most of them turned to prostitution as soon as they were remotely old enough. Kelly Stownar rescued Emma from this fate, or worse, by taking her in as a maid-of-all-work. Mrs. Stownar taught Emma all she needed to know to have a trade in life and survive.