I have no contact with my father or his new wife. Last year I got a Coach purse as a Christmas gift from them and I felt like they were (very poorly) trying to buy my affection back. I heard later on that wife thought that an expensive purse would be the best gift in the word, because what woman doesn't like them? Then when I responded with a note that just said thank you and made no further contact, they were hurt.
If your daughter isn't speaking to you for whatever reason, no matter if it's the truth to the rest of the world, whatever reasons she has is the truth to her. If you don't have open lines of communication, a gift so heartfelt and important may push her away further. At this point if my dad tried to send me something like that, I'd send it straight back to him because I don't want the social obligation of thank you note and further communication such a gift entails. I'm not willing to be the "greedy" one because I take everything without something in return, and I'm not ready to give anything in return.
Please please please, OP, think this over carefully. If you're not absolutely sure without any possible shadow of a hint of a doubt that your daughter will appreciate this gift and further contact between you, do not send the pendants. A note is fine, something very bland and vague. I like the idea a PP had of a store bought gift card saying you're thinking of her. It is literally no pressure for her to respond to it, she can do what she wants with that information, but a gift does entail some sort of obligation to return contact.
I'm glad you're getting the help you need, and I'm glad you're not alone in it, but please be careful moving forward and think of your daughter's healing as well as your own.