She blamed herself for being an unworthy daughter.
Tips
history
Literally "not resembling": originally meant a son who fails to live up to (resemble) his virtuous father. Now it also broadly labels unscrupulous people, especially in fixed collocations: 不肖子孙, 不肖商人, 不肖之徒.
mistakes
不要 confuse with 不孝 (bùxiào, "unfilial"). Same pinyin, different character and slightly different meaning. 不肖 = unworthy of lineage; 不孝 = failing to care for parents.