What is the title of a YA/teen book where a girl forgets her sister’s death, buried under a rose bush, and her father lives as his twin?

I read this book a few years ago (around age 14) and it left a really strong impression on me. It’s a dark mystery/psychological thriller, and I remember the plot roughly as follows:

The main character is a girl.And it starts at around when she and her sister were the age of around 7 and 6​​​​ respectively (disclaimer I am just guessing here as I can't remember what age they were exactly). From what I remember she is described with dark hair fair skin rather tomboyish whereas her sister is the opposite blonde and pink and rosy.

Unfortunately the sister was groomed or manipulated by their uncle. The main character may have been targeted too, but she wasn’t as gullible so she turned out not being a direct victim of the abuse

One day, the uncle tried to lure them both into the basement. The younger sister went in and the uncle sa'd her or was about to, but the father arrived just in time.

One detail o forgot to mention their father and the uncle were twins. When the father intervened, swinging a metal pipe aimed at the uncleuncle. .the fcking pdf used the little sister as a shield. She was hit by a pipe and died from blunt force trauma.

The father then killed the uncle, buried the little girl under a rose bush, like as in to cover the murder and pretended to live as his twin. So her father tobegin with had never been a good parent, rather an alcoholic.

But after he main character somehow forgot these events due to trauma.

She grows up, gets married, and has a child who looks exactly like her sister, but tragically the child dies falling down the stairs at age 3. She blames herself because she designed the stairs.

Later, the buried sister is dug up from under the rose bush.

The book ends with a cliffhanger, with the father chasing the main character through the woods with a gun.

I don’t remember the title or author. The sister who died might have been named Rose.

If anyone recognizes this book, I’d really appreciate your help identifying it! ​