That's how they always phish - "hi" or "how are you". NEVER "Im so sorry for all I did, I want you back can we meet and talk" or even "can we talk". So pathological they are. Just throwing their line out to their obsessed victim so he bites and they get another dose of ego boost.
Classic! And followed with a sad song that supposedly expresses precisely and accurately all feelings and thoughts! I find it really convenient, because it is up to a receiver to pick up the key line and put the emphasis. Also saves time for the one who sends it, and the most important - they are not really accountable for the words that are said by someone else, are they? FB/email, "hi" and "how are you?" and a link to youtube - an essential BPD toolbox!
I think this shows that marriage so far has not gotten rid of the BPD or whatever her issues are.
Exactly! And she needs to deal with those problems and show you that she is more responsible in her thoughts and actions besides writing one-word phishing messages and links.
my advice - wait with replying a bit more... .7 weeks is a very short time for healing... .You seem to understand very well what is happening with her. If she has more to say - she will write. But again think, feel... wait... and then act. Be strong!