To ask do I tell my dd?

I have a similar dynamic with my teen dds. I remind the ‘easier’ one how proud I am that she doesn’t need as much help. That she has her independance. Her sibling was suicidal and we just needed to be there more to keep her safe.

somewhat past the worst of it now (both still teens) and I give the ‘easy’ teens more of my time. I remind them that I am like nanny McPhee and there when they need me but I will back off when I can see they can do things on their own.

I am sure as they get older there will still be resentment. It can be an impossible situation.

I wonder if her “I’m the easy one” is a dig at how she feels about being labeled as that as a child.

i think you need to have a proper conversation with her and start to repair the damage done rather than making the damage worse!

But tl answer 'do I tell her?' Will you tell dd2 how difficult and demanding she was as a child?

So are you telling her she's wrong in saying she was unhappy as a child?
Did you ever ask her as a child or like pp was she a glass child who just had to get on with it?
Now dd2 is doing well, if she came to you with an issue would you shut her down too or listen and give all your attention again?

I think you should maybe consider family therapy and it might be helpful to acknowledge that she got the raw deal as kids.

It's really toxic to have your dc talking so openly about who's the "easy one", where did that come from?

I definitely don't think you should attempt to make her feel bad for having difficulties related to her upbringing. It would be giving a message that your relationship is dependent on her continuing to be the good/perfect child. She's entitled to her feelings!

I had a "difficult" twin and an "easy" twin now both adults. I am so sorry for how the "easy" one was unseen and unattended to in comparison to her twin, when they were children. He needed more parental input and time, and she gave us the space to do that for him by being "easy". But while it may have been necessary and easier at the time, it absolutely came at a cost to the easier child. I have seen this, as I reflected on my parenting now they are adult, and i apologised to her. I urge you to do the same. One child gets less attention than their sibling because they don't demand it. But they wanted and needed it, and didn't get it. So it affects them in adult life, of course it does.
She's having her turn, if you like, at pushing those barrier and testing your love for her, which she didn't do growing up.

She’s allowed to have hurt feelings, she may feel like she was a glass child. Her own difficulties may have been put aside for her ‘louder’ sister’s sake - she may be ND herself and it went unnoticed as there’s evidently a familial link.

I think you are missing the point. I think you need to address her concerns.

Sit her down and tell her that you have recognized that she is really upset and has been very angry and resentful about the fact you prioritized the needs of her younger sibling. Tell her all the things you are going to do to make her feel special and important in the future so she can stop feeling resentful.

It's not too late but she doesn't need to hear that she is more difficult now.

I wonder is she is resentful of recieving less attention and support and feels/felt she needed more from you when she was younger.

I think you should sit down with her and explain to her how it hurts your feelings when she says stuff like that to you . Just make sure you are calm and clear. Explain to her she was a wonderful child but now she needs to sort her attitude out .