Nimbus Rider. Web Surfer Series, #2

Alex-Sander McGregor seeks to be reunited with his kidnapped foster daughter, Mercy. In the Catastrophe, her human mind and her avatar become lost on Canidae Mundus, a planet in the alternate universe generated by Alex-Sander's cybernetic brains. Canidae Mundus is home to the Labrans and the Jackals, humanoid canine races created in cyberspace for a fantasy franchise. A loving Labran family adopts Mercy from an animal shelter.
After her kidnappers' abuse and neglect, she soon forgets she needs to be found. Meanwhile, their tech brand's new rival, Nimbus Rider acquires Alex-Sander's ex-users, including his estranged younger brother, Chance, who signs a lifetime contract obligating him to work for Nimbus Rider. It's Chance who needs to find Mercy, but he resents her stepdad, Elisha Gabrielson, for being raised with Sander.