Oh, I want to hear how this saga went.
As others have mentioned, be careful not to behave as if she is a "stereotypical" Aspie. There isn't anyone who comletely fits the stereotype.
That being said, I recognize so much of your writing in my relationship with my husband. He is very sweet and I love him more than my command of the language will allow me to express, but sometimes.....
Yes, it is all about him. He will return a compliment, but it is "forced." He explains that he has several mental protocols memorized. If I give him a gift, he says "Thank you," but then he either tells me what he needs to go with it or asks how much I spent on it. In his mind, he is "furthering the conversation." Now that I have learned about Aspies and have had several years to learn his personal attributes, I can usually see his side and appreciate his efforts to make sure I feel appreciated.
The good side is I ALWAYS know where I stand with him, he cannot keep a secret from me, and we tend to agree on most everything. I know it is challenging to see a gift on the floor, but I have a hunch she did not mean it to be disrespectful or unappreciative. While an NT would think "Aw, you remembered I like root beer", an Aspie is more likely to think "I told you I liked root beer and you got me some." it was an exchange of information as opposed to a special gesture. When she drinks the root beer, it will taste just as good to her, though.
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"One lab accident away from being a super villain." Leonard describing Sheldon in The Big Bang Theory.