I am specifically referring to inmate-on-inmate SA. As prisons are typically segregated by gender, the offender and victims would both be female in this case. Guard-on-inmate SA on the other hand is mostly male offenders as one might unfortunately expect.

[–] stebo02@lemmy.dbzer0.com 2 points 2 days ago

Yeah I guess I didn't think that through...

I found this source that says:

The rate of inmate-on-inmate sexual victimization [PDF] is at least 3 times higher for females (13.7%) than males (4.2%). This has been attributed to the fact that a majority of prison officials do not view female-on-female sexual assault as “true rape,” making them less likely to reprimand inmates. Furthermore, as the female prison population has grown at a dramatic rate, states have been unable to keep up. Therefore, female prison facilities tend to be overcrowded and poorly designed, making them difficult to police.

So you're partially correct but it's not because women in prisons are more likely to rape another inmate.