With regard to Hermanns specifically, are there differences between the genders with regards to keeping them, care, personality, health etc? Sorry if this sounds stupid but I am used to rats, where there are certain goods that males can't eat, females are more prone to mammary tumours and personality-wise boys tend to be more laid back and calm and gis tend to be livelier and into everything. So that's the kind of thing I mean. For a new owner would you recommend one gender over another?

Hello KateR,
There's little difference. Males tend to be more active & are therefore a good choice. Single females sometimes lay eggs, though this is not common, but is something of which any new owner needs to be aware.
As you are hoping for a "rescue" (your post of Aug 13th) as are many others, it may be a case of being grateful for what, if anything, you are offered.
Regards
Tom