Similarly, you might feel that your family member is obviously trustworthy and known, and I’m sure that’s true in your individual case. But it’s also entirely reasonable and in fact quite responsible for your boss/company to decide that as a matter of policy, unaffiliated third parties can’t be in the hand-off chain for company equipment, because even if your family member is probably fine, there’s that 1% chance that something goes wrong.
It’s not just about trustworthiness; for example, what is the company’s liability if the family member gets mugged while transporting the equipment? There are all kinds of wildly unlikely things that we regularly gamble on in our personal lives but which are deeply unwise to gamble on when you’re rolling the dice for an entire office. Risk tolerance is just different when you scale up.
I also notice that you describe the first incident as asking your manager if she’d be okay with it, and the second incident as letting your manager know that it would be happening. I know that’s not the meat of your comment and might just be a turn of phrase, but it could also explain the different initial reaction and might have raised (valid?) concerns that you don’t understand what a big deal this is, as well as concerns that this might be SOP for you or that this might be happening more regularly in the future, which could explain her otherwise odd insistence that you take the laptop home every night.
On that point, I do agree that that seems like some bizarre reasoning. The only way it potentially makes sense to me is if she was seeing it as a binary of either “Janeway takes the laptop home every night and sometimes WFH unexpectedly” or “Janeway leaves the laptop at work every night and has a non-company person pick it up sometimes.” Obviously that was not the actual choice being offered, but speaking from personal experience, I think there’s a decent chance she simply didn’t understand how ADHD fundamentally impacts recall and habit-forming. She wasn’t hearing you when you said it wasn’t an option, because it’s really difficult for some people to wrap their minds around, even when they should really know better. That said, the appropriate accommodation WAS the secure locker, not a license to ignore security protocols, no matter how ridiculous you personally find them. (I have separate thoughts about the efficacy of Dx disclosure but this is already way too long a comment!)
Finally, others have mentioned avoiding WFH when you’re sick, and I theoretically agree but I’m also in a position where sometimes it really is the best option; I get it. But if your work is that essential, either a colleague (you can tell I’m in higher ed/nonprofits, hah) or a courier service should be the one to make the equipment transfer. Friends and family should be the absolute last break-glass-in-case-of-emergency resort, and I can see why it might’ve been alarming that you don’t seem to acknowledge that, even though it doesn’t sound like your manager handled it very well.