Teensy bit of backstory on this one. Feel free to skip this section here if you want to just jump to the question.
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In our Dark Heresy campaign, our party's Inquisitor was killed, and the cell have been pursuing the trail of his killer ever since. During recent sessions we found that the cell's Interrogator had also been killed, leaving behind an infant daughter.
One of our party cell had been very good friends with the Interrogator and decided to raise the Interrogator's daughter as his own. However, he also did not want to expose the infant to danger and so left the girl with a relative of the Interrogator.
....When he did so, he also dropped a tremendous bucketload of information that he shouldn't have. Said relative was essentially a standard Imperium citizen, and he more-or-less told him almost every detail as to the case the Interrogator was pursuing when he died, among which included a budding civil war within the Inquisition, a planet completely consumed by Chaos, chaos rituals, the death of an Inquisitor, and several other things that should absolutely have been classified.
I should note that the relative in question hadn't even been AWARE his brother worked for the Inquisition. The last he'd heard his brother was working for a scribe.
Now my character just found out about how much his fellow acolyte revealed to this man, and, as the relative isn't too far away, is almost certainly going to take a detour to make sure the relative in question never speaks to anyone about this. In the typical 40k way. After that, I'm fairly certain the next step would be to submit the girl to the Schola Progenium and that would be the end of it.
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What bothers me about the above situation is I really don't want to be "that jerk" who went and smashed another player's character motivation to pieces. His character is clearly invested in the girl, and the player too seems invested in that little bit of a sidequest of: "My character, the foster-dad". I don't want to just go and take that away from him.
But at the same time, I don't see many "in-universe" alternatives, besides sending the girl to the Schola Progenium.
At least not alternatives that won't end in the party Scum and Psyker going at each other's throats.
I've spoken about the issue with the GM and even he seems uncertain as to what I should do in this situation, as he agrees with me, that the course of action seems the most typical of the setting, but also agrees with me that taking the daughter away from the player AS WELL as basically shooting his foster-family plan in the head wouldn't be fair to the guy playing the Scum.
Can someone come up with a possible thing to do with the daughter of a dead Interrogator, besides sending her to the Schola Progenium? Or otherwise come up with another possible solution to this issue?