I agree with SGB when it comes to someone as old as the OP's DD, who can make that choice.
For me, I rely on the support of other bereaved parents, and hope I support them, too, because from my point of view there is no way to really help me, IYKWIM, short of the impossible, and the only ones who truly can understand and with whom I feel comfortable expressing my feelings are with those who walk this road, too.
For our children, however, we have chosen the help offered because of their ages at the time their sister fell ill, the circumstances surrounding her condition and her death. The 7-year-old, in particular, has lasting memories of her sister and certainly of us following her death. The 4-year-old, too. And although we are as supportive as we can be, things came out during play therapy, particularly for the 4-year-old, and art and play therapy for the 7-year-old that they can't really express in words yet, they are just too young.
They can't say, 'I'm scared that if I get sick enough to go to hospital, I'm going to die like my sister. It makes me really anxious.' Or, 'I feel really out of control.'
Some close friends of our family, one of their two sons, the elder, he drowned when he was 6, 33 years ago. The other son was 3. I got to have a long chat with him, the first time I'd ever been able to in person with the sibling of someone who died as a child.
His perceptive meant a lot. His brother was not spoken of in the home. It was thought that, as he was too young to remember, it was best not to 'upset' him. This was the prevailing thought at the time, but it damaged him.
For those who do not believe grief and loss damage people look no further than Queen Elizabeth I's childhood and adolescent letters to her friend Robert Dudley. She made a vow to herself early on never to marry or have children because all that she perceived and experienced of it around her was death for the woman. She stuck to that promise.