In 1858 when Dutch-Japanese Treaty of Amity and Commerce was concluded, Siebold's banishment was withdrawn, and she reunited with her father Siebold, who came over to Japan again, in Nagasaki and she learned Western medical science (Western studies) under her father.
1858年（安政5年）の日蘭修好通商条約によって追放処分が取り消され、1859年に再来日した父シーボルトと長崎で再会し、西洋医学（蘭学）を学ぶ。