Well, I suppose they could find someone to fit the bill. And Eva Damen, although looking close to the part is a tad small for the role (but perhaps some elevator boots would do the trick as she's 5'9''). It's going to be a hard role to fill if you want a perfect casting. I'm eager to see who they sign.
But think about it this way: if you want "ugly bordering on transgender" as the qualifier, would YOU want to be the agent telling some woman "yeah, you'll be good for this."
Oh, and she's not equal to Sandor in size and weight. Over 6 feet? Check. MAYBE a smidge taller than Jaime (and he admits she's stronger), but not 6'6''. Mannish? Sure.
Too bad Dot Jones is too old for the role. She'd be perfect.