HARTFORD, Conn. -- A woman whose 6-year-old daughter was killed in the shooting at Connecticut's Sandy Hook Elementary School is expressing her grief over the Orlando nightclub shooting that left 49 people dead.

Nelba Marquez-Greene posted a letter on the memorial Facebook page for her daughter, Ana Grace, who was one of the 20 first-graders and six educators fatally shot in December 2012.

In it she describes how hearing about the Orlando shooting took her back to the horror she felt as one of those waiting to hear news about a loved one.

"I am sorry that our tragedy here in Sandy hook wasn't enough to save your loved ones," she wrote. "I tried and I won't stop trying. Don't you dare even listen to even ONE person who may insinuate that somehow this is your loved ones fault because they were gay or any other reason. Nor is it God's wrath."

Marquez-Greene tells the victim's families they are on "forever journey." She advises them to embrace the love that will come their way and delete, ignore or put aside "the ugly."

She also urges people not to send money to Orlando until they know it will be received by the victims and not "organizations designed to benefit from tragedies."

"America's mass shootings should not be the United Way's pay day or a specific town's funding source to build a senior centre," she said.

She advises friends that victims will need their help and urges people to bring up gun violence in their houses of worship and community groups.

She also promises her family will learn about each of the Orlando victims and say their names aloud.

"We will remember your children," she wrote. "As you remembered and learned about ours."