I do not know LIT... While a "Happy Thanksgiving" wish is always nice, it might not be enough to give her the main message, which is that you regret having lost connection with her and you are asking her to reconnect.
I was in a similar situation with a "Happy Birthday" wish from a long forgotten relative. It caused me more confusion than anything else. I was wondering why this person suddenly decided to wish me a "Happy Birthday". Was it just a random act of kindness or did they expect me to reply, or what was I supposed to do. In my case it was more an act of ambivalency about whether we should re-connect or not. But in my opinion just a wish is not enough to reveal one's intentions to reconnect with a long forgotten relative. You should somehow deliver your message to her.
I was in a similar situation with a "Happy Birthday" wish from a long forgotten relative. It caused me more confusion than anything else. I was wondering why this person suddenly decided to wish me a "Happy Birthday". Was it just a random act of kindness or did they expect me to reply, or what was I supposed to do. In my case it was more an act of ambivalency about whether we should re-connect or not. But in my opinion just a wish is not enough to reveal one's intentions to reconnect with a long forgotten relative. You should somehow deliver your message to her.