Which part is the family name?

The first one. Both patterns lead with the family-name slot, so in Sotheara Chum the leading Sotheara comes from the 250-entry family-name bank and Chum is the given name.

How are these spelled?

They use the conventional Khmer Latin spellings as stored in the banks, which is why you see clusters like Chh and longer given forms such as Keoraksmey.

How is this different from the Thai or Lao sets?

Khmer leads with the family-name slot, while the Thai and Lao sets place the given name first, so the three read as distinct orders.

Female Khmer Names · Khmer Name Generator

About female khmer names

How female khmer names are built

Each name is written family-name slot first, given slot second. The 250-entry family-name bank leads both patterns: family name plus a male given name (200-entry bank) or plus a female given name (220-entry bank). Sample output includes Sotheara Chum, Ngin Dara and Eat Keoraksmey.

Sotheara Chum
Sotheara + Chum
family-name slot first plus male given slot
Ngin Dara
Ngin + Dara
family-name slot first plus female given slot
Eat Keoraksmey
Eat + Keoraksmey
family-name slot first plus female given slot

Naming notes

The leading slot is the family name even though it can read like a given name to English speakers. The 250-entry family-name bank feeds both patterns while given names come from a 200-entry male slot and a 220-entry female slot. Spellings follow the conventional Khmer Latin forms as stored. This is a Cambodian label set, distinct from the Thai and Lao sets, which lead with the given name.

Questions about female khmer names

Which part is the family name?: The first one. Both patterns lead with the family-name slot, so in Sotheara Chum the leading Sotheara comes from the 250-entry family-name bank and Chum is the given name.
How are these spelled?: They use the conventional Khmer Latin spellings as stored in the banks, which is why you see clusters like Chh and longer given forms such as Keoraksmey.
How is this different from the Thai or Lao sets?: Khmer leads with the family-name slot, while the Thai and Lao sets place the given name first, so the three read as distinct orders.