Translation:She felt worried about the result.
I asked the same question (on feeling happy) on the Facebook site, https://www.facebook.com/groups/duolingo.esperanto.learners/?ref=bookmarks and got the following response from Lee Miller:
Note that if you were to say "Mi sentas min feliĉan", the meaning is "I feel the happy me". In other words, I'm a happy person, and I'm feeling myself in some way.
"Mi farbis la domon blankan" means "I painted the white house." "Mi farbis la domon blanka" means "I painted the house white".