I sketched out what I thought female hrothgar may look like on ms paint and also put down my thoughts. I'm not saying they
should look like this or anything. This is just a guess from what we've seen so far from murals and concept art.

image link for closer viewing:
link
There will be several facial options to choose from of course, but I'm thinking they will be a little bit more delicate compared to the males. I think they will still look feral, and will probably tower over most characters. The head in the concept art looked a bit small (the lack of hair didn't help either), but I'm not too worried about it. I think the finished model will look just fine.
I don't think they will be big and bulky like some of the other art in this thread, but I do think that looks really cool and wouldn't be against it. They will probably be feminine/curvy.