This was a full-length novel I read a couple of years ago.
The father is the lead dev (or the security head I forget which) of a MMORPG with full VR immersion. There is some kind of coup by some players in the game. This leads to the game being locked down with the players stuck inside the game. The daughter and her party are stuck in there and start off on a quest.
I remember that the attack was a synchronized attack from both inside and game and outside the game.
This sounds somewhat like the movie ExistenZ, which did have a tie-in novel published in 1999. I do not remember the father-daughter aspect in the movie, but have not read the book.
You are in a society where game designers are superstars and players can organically enter their favorite games. . . . A society where no one is more desired than Allegra Geller, the hip gaming goddess whose latest system, eXistenZ, takes a quantum leap beyond anything ever imagined--tapping so deeply into its users' fears and desires that it blurs the boundaries of reality.
Fleeing an assassination attempt from Anti-eXistenZialists determined to destroy the game and its creator, Allegra finds an ally in Ted Pikul, a young executive turned novice security guard sworn to protect her. Seeking shelter within her creation, Allegra persuades Ted to play the game, and the fugitives find themselves in a phantasmagoric world where existence ends and eXistenZ begins, a fantastic place where nothing is as it seems and the villains are all too real--and all too deadly.
Second theory after a bit of searching would be the Otherland tetralogy by Tad Willams (1996-2001), which sounds as though it would support various subplots of dropping into quasi-cyber-realities. (And now I see it's already been nominated.)
The story is set on Earth near the end of the 21st century, probably between 2082 and 2089, in a world where technology has advanced somewhat beyond the present. The most notable advancement is the widespread availability of full-immersion virtual reality installations, which allow people from all walks of life to access an online world, called simply the Net. Tad Williams weaves an intricate plot spanning four thick volumes, and creates a picture of a future society where virtual worlds are fully integrated into everyday life.
Something very similiar to this happens in The Demi-Monde: Winter (2011) by Rod Rees.
The Demi-Monde is the most advanced computer simulation ever devised. Created to prepare soldiers for the nightmarish reality of urban warfare, it is a virtual world locked in eternal civil war. Its thirty million digital inhabitants are ruled by duplicates of some of history's cruellest tyrants: Reinhard Heydrich, the architect of the Holocaust; Beria, Stalin's arch executioner; Torquemada, the pitiless Inquisitor General; Robespierre, the face of the Reign of Terror.
But something has gone badly wrong inside the Demi-Monde, and the US President's daughter has become trapped in this terrible world. It falls to eighteen-year-old Ella Thomas to rescue her, yet once Ella has entered the Demi-Monde she finds that everything is not as it seems, that its cyber-walls are struggling to contain the evil within and that the Real World is in more danger than anyone realises.
Could it be Heir Apparent (2002) by Vivian Vande Velde?
From Wikipedia:
Heir Apparent is a science fiction/fantasy novel by young-adult fiction author Vivian Vande Velde, about a girl who becomes trapped inside a looping virtual reality role-playing game called Heir Apparent [...]
Dodging the protesters, she enters the arcade and gets hooked up to Heir Apparent, a single-player RPG in which there are practically endless ways to win or lose. Giannine's character, Janine de St. Jehan, is the illegitimate child of the recently deceased King Cynric, who pronounced her heir to the throne, passing over three legitimate sons.
Her task is to survive the three days (which will only last thirty minutes in the real world) before her coronation. Anytime her character dies, she will automatically be sent back to the beginning of the game.
I am completely sure this might be incorrect, but posting to help out the asker.
The story you are describing is very similar to Tron (1982). Maybe Tron was made by referring the story that you are telling. I am not sure which it might be, but there you go. The getting stuck inside a game and being created by the father and all reminds me about Tron.
From IMDb:
A computer hacker is abducted into the digital world and forced to participate in gladiatorial games where his only chance of escape is with the help of a heroic security program.
The book Heir Apparent fits some of the criteria that you are looking for.
Heir Apparent is a science fiction/fantasy novel by young-adult fiction author Vivian Vande Velde, about a girl who becomes trapped inside a looping virtual reality role-playing game called Heir Apparent. [...]
Dodging the protesters, she enters the arcade and gets hooked up to Heir Apparent, a single-player RPG in which there are practically endless ways to win or lose. Giannine's character, Janine de St. Jehan, is the illegitimate child of the recently deceased King Cynric, who pronounced her heir to the throne, passing over three legitimate sons.
Her task is to survive the three days (which will only last thirty minutes in the real world) before her coronation. Anytime her character dies, she will automatically be sent back to the beginning of the game.
