Lijmberta "Bertha" Aaltje Valkenburg (1862âÂÂ1929) was a Dutch artist.
Valkenburg was born on 5 January 1862 in Almelo, the daughter of painter . She attended the Rijksakademie van beeldende kunsten (State Academy of Fine Arts) and the Rijksnormaalschool voor Teekenonderwijzers (National Normal School for Drawing Teachers). She studied with August Allebé. In 1910 she married Hendrik Willem Adriaan Krook van Harpen. She was a member of Arti et Amicitiae and '.
Valkenburg died on 1 March 1929 in Laren, North Holland.