People like that can be nice but they are so insufferable when they take more than their given space. I don't fly much but will be more soon. I am "larger" than the norm but not fat. Being somewhat tall and broad sometimes sucks.
At least she was nice, otherwise you might have had a REEEEEE for hours on end. It's still not right but its better than it could have been.
If you are a tall person and large stature I would seriously consider flying economy plus. It is between business class and economy and costs a little more than economy but you get a bed to stretch out on. I am doing this next time I fly to Asia from NZ as it is a 16 hour flight not including laybys. It took me 21 hours to fly from Thailand to NZ with 5 hours layby or changing flights.
I always do that when I can, though, like I said, its been a while. I pay for my space. Even if its not what I need I don't mess up the space of others around me and try to take up as little space as I can.
One of my bosses came back about a week before me and he's about 6 foot 5. He said he had to stand up a lot and walk around so at least when the planes in the air you can actually get up and move around a bit. Helps with body pain from sitting too long.