Maria-062

Maria-062 is a Spartan in the Halo Graphic Novel. She tests out the new MJOLNIR Mark VI battle armor in Songnam, Korea against a squad of ODSTs before it is sent up to Cairo Station for the Master Chief. She mentions that she had retired to start a family.

In the Halo novel "The Fall of Reach" just as the remaining 30 Spartans are informed of their new mission to bring a prophet to Earth for talks on ending the Human-Covenant war, it is said that out of their 37 (sometimes mentioned either 36 or 37) that there had only been 3 KIA and 1 SPARTAN too wounded to continue active duty. Since the release of the Halo Graphic Novel, it is widely assumed that Maria is the wounded Spartan mentioned in Halo: The Fall of Reach, but other evidence indicates that Cassandra may be that wounded Spartan.

Also possible, is that she is one of the three surviving SPARTANS who weren't present during the briefing at Reach, due to being engaged elsewhere.

She says to the senior officer at Songnam that "Once John gets a hold of this armor, we'll all start sleeping a little better at night."

In the Halo Graphic Novel it is also mentioned that she is in the Reserves which makes it possible that now the Covenant have invaded Earth she may return to the Spartan project and fight in future books or Halo 3.

Inconsistency
It is extremely unusual for ONI to allow a Spartan, a genetically altered, extremely classified military operative, to leave military service and live a civilian life. Despite the fact that most augmented SPARTAN-II subjects have a repressed sexual drive, she has quoted having children whom are likely to have excellent physical properties like their mother, but without the augmentations, and could reveal the Spartan program to the public. It is also possible that her children could be recruited into the Spartan-III Project, but highly unlikely as Ghosts of Onyx stated that all of the SPARTAN-IIIs were composed of orphans from fallen colonies. Also, the idea that she retired may just be a cover story for people that have read the HGN but not the full novels. In addition, The Fall of Reach clearly states in the list of Spartan augmentations that the "Catalytic Thyroid Implant" suppresses sexual drive, meaning that it is very strange that she could even have children at all.

A suppression of sexual drive means that a person doesn't actively seek sex, enjoy sex as much as the next person or at all. But this does not necessarily refute the possibility for a Spartan to reproduce, as a lowered sex drive doesn't mean that the gamete number is reduced, just the urge to put those gametes to use.

As a additional note: In real life, there are any number of successful pairings where the man or the woman gets no particular desire for or pleasure from sex within the marriage or at all. They still have kids. Some are homosexuals who want kids or are living as straights for reasons all their own, while some others simply have low sex drive and don't mind pleasing their loved one, or again want kids. There are other varieties of the situation, as well.

It's possible that ONI allowed her to retire to promote the myth that Spartans are invincible, as what better way to show that, than to show a Spartan retired with children.