The surname would be best "binti Haji Prajitno", as suggested. But what about names like the Balinese. Their system is extremely difficult. Firstly, because they are Hindu, they have a caste name. For the lowest caste (Jaba), it is I for men and Ni for women. Then they have a position name. First child is Wayan or Putu, second child is Made/Kadek/Nengah, third child Nyoman/Komang and fourth child Ketut. After that they have a personal name. As an 'adopted' balinese (because of my close ties with the community, not because of blood) I am Ni Made Susanti. That tells everyone I am lowest caste, second child and called, by my family, Susanti.
If I were the next caste up (Wesia), the caste names are I Gusti and Ni Gusti.
The Satria (nobles) have the title Anak Agung, Gusti Agung or Cokorda and they do not use the position names.
The Brahmana (priestly caste) are known by the titles Ida Bagus and Ida Ayu and do not use position names.
None of them have any hint of a surname, not even a hint at the identity of their parents, nor do they use a clan name, though they might know what clan they belong to.
Now that is a challenge for any genealogical site. LOL