Zepheera’s healing factor is inspired by the mutant gene à la X-Men. Similarly, the gene is carried by and passed on through males. Zepheera’s father had the same healing factor and passed it on to her, but none of her descendants will have it.
As to the extent of the power: it’s not as strong as, say, Deadpool’s or Wolverine’s, but most wounds will heal. This includes but is not limited to cuts, burns, and broken bones, but excludes regrowing lost extremities and mortal wounds. Zepheera is as susceptible to death as any other borrower.
Borrowed Time and Space 