Big question I have about Pretty side story

So we know Pretty's corpse was still lying at the podium in the hall and it got taken and likely converted by DEEP/MMR into the Armament Star right?

Why didn't Oswald at least ask for his daughter's corpse or brain yet? I know the concept of a corpse doesn't really apply to Nikkes, but I would think he would at least ask for some physical trace of her body lying there as a keepsake or something, or for some sort of burial rite. I genuinely think the writers neglected this or deliberately brushed it over because they did not want Oswald's storyline and the DEEP storyline getting tangled up.

Alternatively, maybe he is aware all Nikkes belong to the Central Government so it would be impossible for him to retrieve a piece of her? This seems like the best explanation so far to me. The problem with this to me is it seems a bit out of character for him to give up on giving his daughter a proper burial like that.

Another theory I have is she was properly buried, but her body was dug out afterwards and they put the soil and stuff back it so it would look like her place of burial was not desecrated at all.