From what I have read there were several sons and daughter for Ramses II and Nefertari:
1. Amenhirwenemef / Amenhikopshef / Sethhirkopshef: First King’s Son, Eldest King’s Son, Generelissimo. The Eldest son of Ramses and Nefertari. Changed his name early in the reign, and changed it again (to Sethhikopshef) around year 20. There is some speculation that he was known as Amenhirkopshef in the north and Sethhikopshef in the south. He was involved in the correspondence with the Hittites after the peace treaty. He apparently died around year 25.
3. Prehirwenemef: King’s Son of his Body, Master of the Horses, First charioteer of His Majesty. Son of Ramses and Nefertari. Depicted in the triumph that followed Kadesh.
11. Meryre I: King’s Son of his Body. Son of Ramses and Nefertari.
16. Meryatum: King’s Son of his Body, High Priest of Re in Heliopolis. Son of Ramses and Nefertari. Apparently visited the Sinai during the second decade of his father’s reign. He served as high priest for about 20 years. He was either buried in the Queens Valley or in KV5.
[the numbers refer to their ranking in the lists of sons by age as far as they can be determined.]
For as far as the daughters are concerned we have Meryetamun, Nefertari II and possibly more.
The children of the other Great Royla Wife Isetnofret include:
2. Ramsesses: King’s Son of his Body, Eldest King’s Son, First Generalissimo. Son of Ramses and Isetnofret. Heir to the throne from year 25 to year 50. Buried in KV5.
4. Khaemwaset: King’s Son of his Body, Sem-Priest of Ptah, High Priest of Ptah in Memphis, Executive at the Head of the Two Lands. Son of Ramses and Isetnofret. Crown Prince from year 50 to 55. One of the best known sons of Ramses. Known as one of the first archeologists. He was famous in ancient Egypt, and later featured as the hero Setne-Khaemwese in a cycle of stories written in the Late/Ptolemaic times.
13. Merenptah: King’s Son of his Body, Eldest King’s Son, Executive at the Head of the Two Lands., Generelissimo. Son of Ramses and Isetnofret. Heir to the throne and for all intent and purpose regent during the last 10 years of his father’s reign. He became Generalissimo after year 50 and Heir to the throne in year 55
Isetnofret's daughters include Bintanath and Isetnofret II.
The relatives depicted at Abu Simbel are sometimes thought to depict family units:
First Southern Colossus: Queen Nefertari, Queen Mother Muttuya, and Prince Amenhirkhopshef
Second southern colossus, Princess Bentanath, Princess Nebettawy, Queen Isetnofret (?) (or: Princess Nebettawi, Princess Iset-Nofret II, Princess Bintanath )
First northern colossus : Queen Nefertari, Princess Beketmut and Prince Ramses.
Second northern colossus: Princess Merytamun, Queen Muttuya and Princess Nefertari II.
Not sure if this completely works, because I think that inscriptions indicate that Prince Ramses was a son of Isetnofret, not Nefertari.
Ir's interesting that on the facade of the smaller temple dedicated to Hathor and Nefertari we see Ramses and Nefertari depicted with:
the princes Meryatum, Meryre, Amunhikhopshef and Rahrirwemenef, a
and the princess Meryamun and Henwati.
I wonder if this may be an indication that these six then are the children of the couple at the time that this temple was built?