。
She's being a bit difficult about things.
Literal
She [topic-は] a-little difficult things [object-を] is-saying.
気難しい (きむずかしい) means 'hard to please, fastidious, particular' — describing someone who raises difficult demands or objections. ことを言っている ('is saying things that are') frames this as an ongoing behavior. The 少し softens the criticism to 'a bit.'