The art is amazing! Although, the very idea hit a lot of warhammer fans in the face like an insult. It's a little bit risky to go along that narrative, just sayin'...

Thank you! And don't worry. Their butthurt provides me with sustenance c:

Awesome stuff. The world needs more female Custodes, no matter what the chuds say! :3

Honestly, Fan stuff? All good. As someone who is fairly hard core 'Don't screw with the lore', you do you, it's fine. And if you want Femstodes or Femmarines with in universe lore? We can work With the lore to do that. You just need to make a planet where ladies are larger and stronger than normal, say they can accept genseed, albeit with moderately higher mortality rates, and it just works. They are borderline mutants, but they are useful and Stable enough for the Inquisition and Mars to not look too deeply. And it now works with the lore, nothing more needs to be done. It's a head node to the lore and all the fanboys are happy. This is truly all that was needed to make a Femmarines chapter that, before all the BS, the fans would have looked at, nodded that it checked out, then paid for to either make a new army, or to augment their Sisters of Battle with. Sisters who are basically female space marines... #Sisters point costs are too high, [Last I checked, 5 sister scouts(130pts) or 10 Space Marine scouts(140pts)...]

The issue is when random assholes go into the established hard lore, the stuff that is calcified as definitive fact, and then change That because it does not fit their new political agenda.

It's like if Disney decided to retcon all of Star Wars to make Green the lightsabers the color of the Sith. Does it truly change anything?
No.
But it is a mental hammer blow to what is normal in universe, and the Fanboys would riot as much as the 40K fanboys do over having decades of well established lore tossed out to do a lot of nothing. (end of the day, adding the booba to Ex-Human war machines changes nothing.)

... Now, if you want some ammo to stir the pot. In the OOOLLLD lore, Rogue Trader era, there were female space marine models. But that was retconed before 40k proper, I think.
Also, Since Custodes are made as one off Master Crafts, rather than with the cookie cutter genseed of Space Marines, it is far more Likely that a Custodies could be made from a female than a Space Marine could.

In closing: We Dig Chicks in power armor, it is why SoB are still played even if they are bottom tire. Just don't color swap our lightsabers and then tell use they were always green, people don't like getting gas lite.