The case can be reported today after restrictions were lifted.
Mr Moustafa, 51. who lives in Nottingham, insisted there was “strong evidence” the defendants should have been tried on more serious charges.
“It is not what we expected,” he said. “It’s unfair and unjust to charge those whom killed or, at least by their actions, led to (Mariam’s) death with such minor offences.
“It is very weak. It is not fair at all.”
He described the failure to inform him of last week’s hearing as “another failure in the case of our daughter”.
“This very simple right was taken from us,” he said.
A CPS spokesman said: “We have worked closely with the police to make sure Mr Moustafa has been kept updated throughout this process and are deeply sorry this didn’t happen on this particular occasion. We have contacted him to offer a full explanation.
“We have also met with Mr Moustafa to explain the charge of affray, the CPS can only charge if the evidential stage of our tests for prosecution are met.”
The teenagers will be sentenced at a later date.