...No. She IS supposed to be really homely. The only thing she has going for her are her big, bright blue eyes.
Brienne was never described as being hideous. She is supposed to be large and masculine with a slightly big mouth. It's supposed to be a subtle ugliness that you're supposed to be able to eventually find pretty in some context if you warm up to her. I swear, so many people that talk about this series don't seem to understand subtle appearances, as if attractiveness and ugliness was a binary issue.
I swear, so many people that talk about this series don't seem to even remember what the books said:
Beauty, they called her . . . mocking. The hair beneath the visor was a squirrel’s nest of dirty straw, and her face . . . Brienne’s eyes were large and very blue, a young girl’s eyes, trusting and guileless, but the rest . . . her features were broad and coarse, her teeth prominent and crooked, her mouth too wide, her lips so plump they seemed swollen. A thousand freckles speckled her cheeks and brow, and her nose had been broken more than once. Pity filled Catelyn’s heart. Is there any creature on earth as unfortunate as an ugly woman?
And the rest of the series she's routinely mocked for her appearance. Anyway, I think the show did the character justice. She wasn't "TV ugly", but they gave the actress the Charlize Theron treatment, and it worked great.