Hi
This is a very common complaint of students.I can understand your daughter's pain
CBSE systen is really pathetic.These examiners get paid per answer sheet.The more answer sheets they check,the more they get paid.Obviously they check hurriedly,to earn more.
In my time,ie,late 1990s,if we wrote to CBSE,they only did the retotalling of marks.They never checked each and every answer again.I am unaware if the current revaluation system has improved.
Still i want to inform you that in late 1990s only,a girl in my locality who always topped in her school got 4 and 6 marks out of 100,ie,failing in 2 subjects.Her parents were very cross.I don't know how they approached the CBSE(maybe legally),they actually managed to get the answer sheet revaluated in front of their eyes and detected a major fault due to which such low marks were obtained.After revaluation,she got her marks in 80s and 90s.
So I feel being assertive and taking help of rightful legal people may help.Yes the system is lousy.So you need to shake it with your assertiveness.