"Aigoo I feel bad for her" => 아이고, (저) 여자애(가) 너무 불쌍해. 불쌍하다 (adj. be in pitiful, miserable situation) is the most common word for pitying some person or animal. There is also 안되다 (verb. had a misfortune). Unlike 불쌍하다, which implies the subject is helpless, 안되다 maintains the respect for the person. So 안되다 is safer to use for respectable people who had something bad happen to them. For example, * This cat is so miserable = 이 고양이(가) 너무 불쌍해. * My friend's family is in such a bad shape from a business failure = 친구네 사업이 실패해서 참 안됐어.