Im split on this, had Flemith transformed into her old women looks from DA:O, I think it would of made a cool contrast to the insane dragon form she was in minutes befor,
Dragon - Old Lady in rags would of been a powerful switch, they could of revamped the rags etc to make it look more dramatic.
At the end of the day, I just think, when making DA:O Bioware didnt plan to make a great deal out of Flemith, but when writing Dragon Age 2, they decided to make her a main character, and also decided to make her look 'related' to Morrigan allot more.
If it had been me, designing her, I would of stuck to an Origins look for her, but oh well, thats the only slight gripe I have with the demo, so not a world ending problem