While I am empathetic to a family who loses both parents, they are not tiny children. Their youngest just finished seventh grade. The word orphan normally conjures images of much younger children.
In regards to what could be done to honor the lives of the fallen teachers, several things come to mind. Gun control is a benign toss of ideology.
Something with a meaningful basis would be to find ways of making mental healthcare a more common aspect of every community. Guns are not the chosen weapon of all public attacks, but what is a common factor is skewed mental stability. Perhaps a Band Aid type event could be organized in honor of all fallen educators to fund mobile mental health units which could make regular scheduled visits to schools across the country. Students could be seen by professionals who could address various concerns such as normal childhood fears and questions, and also provide a place for kids to anonymously tell “safe” adults about concerns they have about acquaintances. Nearly all school attacks are made by someone who was known to harbor feelings of desire to get revenge, or to be harmful to animals, or other red flags. These situations rarely get reported because people are frequently confused about who could do anything about their concerns for such acquaintances.
The units could tour various areas, keep files, but switch the professionals around, so people who are uncomfortable with one, would later have chances to see others. I think for many it would be a more preferable resource than having in school counseling with someone who may be crappy, but all the particular school can afford. Not that in school counseling should be replaced, but in countless cases there should be an alternative readily available. The units should be primarily available to students, but not exclusively.
Another fund raiser could be a book compilation of memories of those teachers submitted by various students down through their careers. The sales could fund needs of survivors of the fallen teachers and students. Friends and relatives will suffer a long time.