For me, a lot of Donna's character is about that, especially juxtaposed with Jody. Donna cares about relationships, and puts a lot of heart and care into them. She notices. She allows her vulnerability to show. She will be there for you, she will save you a seat, she will do the annoying thankless little things that make a convention work. She's smart, and doesn't seem to pay much attention to that. She sees people and gives them a lot, does a lot of emotional work and nurturing
S he so deserves to be treasured. Not for being able to kick a vampire's ass, that is not what makes her awesome.
In 11x07 I would say most of Donna's awesome didn't show. It is typical of these writers, I won't get into my rant about them writing everybody at their shallow worst (Sam would *not* call Donna that, no). For me, that was a significant part of why this episode did not so much work for me.