Just ringing in with my two cents! Thing is, Made, this is one of those things where you're really just going to have to listen to your heart on it. Even DR says something like, "It's your sitch, so you'll have to be the one to decide how you want to handle it." You will know what you need to do when it comes time for it.
For me, personally, if it was my W's b-day coming up, I wouldn't send anything. I'm quickly realizing the power of going dark. At first, it feels terribly cruel, and you are imbued with the fear that you will push her away with your newfound "coldness." However, there's nothing cold or punishing about it. Your W has made it very evident that she doesn't want you in her life anymore, so give her a heaping helping of space. Good for you, and good for her, too. Gives her time to think about what she might be missing, and gives you time to heal.
Nothing is louder or more resounding now than your silence.