At this stage, nothing would surprise me about this thread.
For one thing, I harbour some slight doubt as to the existence of the (much maligned) sister.
The extraordinary degree of emotion of the OP's original post - that is, if it is at all genuine and not an Apple fishing expedition, or a troll thread, - suggests to me that rather than an unfortunate sibling, he himself might have been the culprit in question.
However, it may not be given to us to learn more about these matters.
I’m with you. I think 941 was the employee or contractor. At the very least, the sister was a ploy to throw off the scent.
Can you imagine how it would have been otherwise?
[Sis]: Hey little bro! Come check out the cool stuff I’ve been working on. Make sure you don’t tell anyone, ok? I could be fired or sued just for showing you this stuff.
[941]: You got it, Sis! I would never dream of taking all the design drawings you have, spending hours re-rendering them to appear slightly differently and then posting them all over the web in an effort to outdo Mark Gurman.
[Sis]: Haha! Better not! Oh, excuse me, I need to take a 45 minute call from upstairs.
[941]: [screen grabs all the design drawings and renders]
45 minutes later
[Sis, on returning from her conference call]: I thought my laptop was open to the new Apple Watch homescreen mockup. You didn’t touch my MacBook did you, little bro?
[941]: oh no, the dog pushed it.