I just wanted to put forward my 2p worth, in defence of your neighbour OP.
I've very recently, within the last few weeks, lost my lovely husband, suddenly and unexpectedly.
No illness.
Just found dead at home.
While I haven't screamed at anyone, in my head I've said "go away, I don't want to talk to anyone just now - and maybe not later, either".
I often don't answer the phone either.
Part of this, for me, is, I can just about muddle along and cope with my own grief but I can't bear to see and hear that grief reflected back to me on the faces and in the voices of others.
I have a really good friend who just instinctively knows when to keep her distance and when a listening ear, tea and sympathy is required.
I have other friends and relatives who will smother me, if I let them. Some of those, I've kept at a distance, for now.
The amount of willpower, grit and effort it takes me to leave my house, at times, is exhausting. Some days I think I'm just not going to be able to regain my composure long enough to make it to the corner shop for a pint of milk. It wouldn't take very much for me to crumble into a sobbing mess.
Your neighbour's nerves are probably stretched to their limit if she's feeling anything like me.
2 weeks is very, very early days.
I'm so sorry she's upset you.
It's nothing that you've done or said or not done or said - it's all to do with her and how she's feeling.
From your description of your previous relationship, I'm sure she isn't thinking of your feelings at all but is doing this as some form of self-preservation for her.
It's just her method of dealing with the horror that is bereavement.
My advice would be, say nothing but just raise your hand to her in acknowledgement and leave it at that