Confused

I'm very confused and don't know if I'm dealing with a Narcissist, but I do know that I have a very creepy feeling about this person and the only reason I've remained on friendly terms is down to the - charm.

My neighbour is very well mannered and charming and at times kind of refreshing with her straight talk.
However, I notice that I only hear from her when she wants something and she always wants something.

We share responsibility for the distribution of funds collected from a guest room in our building. I am co-signatory on a cheque book. Yesterday she said, I don't want to be bothering you all the time to sign cheques, so would you sign a few blank ones to save you the bother. I said No, I won't sign a blank cheque. She would not accept a no. Instead she accused me of not trusting her, quoting another example of my 'mistrust' that I declined her offer to keep a spare key to my flat. I found myself justifying my position after a long and drawn out interrogation about why I didn't trust her.

As far as I'm concerned, if she were only interested in not, bothering me, then my refusal should have been enough.
A more creepy aspect to my neighbour is, that she buys the same funishings that I have in my flat and some of the same clothes that I wear, then behaves as if it was her idea and I copied her.

I took her to a social club that I attend, she spent the evening chatting to various people, then when I started a conversation with a male friend, she stood up and announced, I want to go now! I told her I was talking and would leave when I finished the conversation. She demanded to know 'how long' it would take, I said I don't know exactly and at that, she stormed out and went home.

She did the same thing one other time, the minute I spoke to a male friend, she demanded that we leave at once.

If we arrange to meet somewhere, she'll arrive very early, then berate me because she had to wait, disregarding my objections that I turned up on time, but it was her own fault if she got there too early and had to wait.

I had a handyman known to both of us, do some work in my flat whilst I was at work and came home to find, he was in her flat doing work.

I don't know if this woman is just plain selfish and insecure or if there's something more serious that I need to be aware of.