"Since you and your colleagues in Congress seem to feel that this is the solution to mass murder, please accept this contribution," she wrote.
"At a time like this, people want to feel safer," one expert told Newsweek.
Russian bots have been busy tweeting about Parkland, gun control, Florida and Nikolas Cruz, the alleged shooter.
The 19-year-old admitted to the slayings five months after it emerged the FBI had been warned he was a potential threat.
Authorities were able to identify the ninth grade student from the Snapchat pictures.
Cruz was charged with 17 murders Thursday morning, and his attorneys claimed that his mental state is that of a "child."
"The FBI was too busy trying to undermine the president to bother with doing it's freaking job," tweeted lawyer and conservative columnist Kurt Schlichter.
The FBI was alerted to Nikolas Cruz after someone with the same username posted a comment on YouTube last fall proclaiming, "I'm going to be a professional school shooter."
Images from Nikolas Cruz's social media account show him asking about modifications to rifles and background checks for guns.