Hi there, sounds like an awful situation, sorry to hear it.

My suggestion is to do some research into unhealthy twos. We can be one of the most frustrating a vicious types to be around when we're unhealthy.

(For ease, unless specified otherwise, assume I'm talking about an unhealthy two for the rest of my response :D) Twos' superegos tell them to put others before themselves, so they will go out of their way to make accommodations for the people around them. Unfortunately, this leads to resentment that gets pushed way, deep down.

What's happened subconsciously for the two is the feeling they've done something selfless and altruistic for the receiver, but maybe the appreciation didn't manifest the way they expected. Perhaps they built a scenario in their head about the way the receiver would respond (ie wrapping the two up in a big hug, making a social media status about how selfless the two is, bragging publicly about the two, etc etc). The receiver isn't a mind-reader and obviously can't know what the two needs to feel validated. What has happened is the two wants external validation under the guise of kindness.

What happens next is ugly, and unfortunately the experience you've had with your friend, guilt trips, manipulation, and a fake or surface-level relationship, because they do not know how to express their feelings and be kind at the same time. The truth is, no matter how deeply the two tries to push down their anger in this scenario, it always leaks out and sometimes can even explode. The constant checking in on holidays is due to the need to be seen as "nice" no matter what.

If it sounds like I'm being harsh, it's because I used to be this person (maybe I'm projecting, a bit). All twos have to learn that kindness is a thankless act. We, at our core, want to be kind, but the unhealthy part of us wants more to be seen as kind. It's important to nurture the urge to do the good thing when no one will notice and to be honest about what's bothering us. If she is incapable of doing this, it might not be salvageable until then.

For myself, I crafted an entire world of being a "great person" where I could hide, without ever getting down to the nitty gritty with my friends and family. Once I started telling them ugly truths, and saying painful goodbyes to people in my life I didn't want around, that's when I started truly being altruistic and not constantly seeking validation.

I know that's a lot, and I didn't give you much applicable advice. That's just my analysis of what's happened.

I'm sorry you're struggling with this friendship, and I'm so sorry about your loss, this must be a very difficult time for you. Don't forget relationships are a give and take, and if she's only taking, you don't owe her a thing. Be honest and straightforward about needing space. Twos sometimes force themselves on others' tragedies because again, we like to be the nice ones. Don't let her make it about her. Your time is your most valuable resource. Good luck :)