Members of the Fantastic Four, Reed Richards and Susan Richards, got married and had two superpowered kids- Franklin Richards and Valeria Richards (or Valeria Meghan von Doom).
Franklin Richards is a powerful reality warper, who became one of the most powerful mortals in the universe from a very young age.
Franklin has the ability to change and transform into any being, and his magical powers have on several occasions caused him to subconsciously change his anatomy to an X-Gene.
At the collapse of the Multiverse, Franklin was able to use his powers to bring about the restoration of the Multiverse, but as a result, he lost most of his powers. Although, he still had some powers saved up for emergencies.
With the loss of his powers and the simulated X-Gene, Franklin stopped being a mutant.
Valeria Meghan von Doom
Valeria Meghan von Doom, originally Richards, is also the goddaughter of Doctor Victor von Doom. There have been several versions of Valeria von Doom.
In Jonathan Hickman’s Secret Wars (2015), she is the biological child of Victor von Doom, who later became his head of science.
In the Secret Wars: The Runaways crossover, she is the headmistress of the Victor von Doom Institute for Gifted Youths in Doomstadt.
Following Victor’s deposition of himself as God-Emperor, Valeria leaves to explore the multiverse with her brother Franklin, her father, Reed, and her mother, Sue, only to return much later In her original appearance.