The basic rule...

1 snake... 1 enclosure.

2 snakes... 2 enclosures.

Regardless of sex and age.

Two females are probably the most cohabitable... but you still need to deal with dominance, issues around feeding, health and stress.

If one snake gets sick from stress... then you will have two sick snakes.

If one regurges, can you be sure you know which one it is?

And they have this pesky habit of, on occasion (not often - but it does happen), eating each other... OK, so technically only one gets to do the eating... but you get the idea.

The only reason to house two together (non socialable animals) is to save costs and space, and those just are not sufficient reasons and/or justification when considering the potential risks.

Bruce