And then something grabbed Cohen's attention: On the wall was a set of directions for what children in class should do in the event of a lockdown drill, written in colorful and bubbly letters - to the tune of "Twinkle, Twinkle, Little Star".
"Lockdown, lockdown, Lock the door, shut the lights off, say no more", the song reads. Say no more.
Go behind the desk and hide.
Parent Georgy Cohen spotted the poem taped to a classroom chalkboard at the school in the city of Somerville.
The post, written on Wednesday, had been shared more than 8,000 times and retweeted nearly 20,000 times at the time of writing.
At her pre-kindergartener programme, the girl was practising active shooter drills and was "excited about it as a game to see if you can stay quiet for one whole minute", Cohen tweeted.
In a joint statement, Somerville Mayor Joseph Curtatone and Public Schools Superintendent Mary Skipper said the poem was an example of a teacher's strategy to "help her young students stay calm and remember the key steps they would need to follow during a drill or real emergency", HuffPost reported.
A poster made by a Somerville kindergarten teacher - with instructions for her students on what to do during lockdown drills - has generated conflicted feelings and a lot of buzz.
It's all done.<em>
Now it's time to have some fun!em>.
Kelda Roys, who is now campaigning for governor of Wisconsin on a gun control platform, recently shared a story about her 3-year-old daughter playing a "game" involving hiding in a corner and remaining quiet.
"I always worry", said one father.
"This sort of thing really makes me question raising my kids in the USA", tweeted one San Francisco-based father. And in place of the usual self-promotion following a tweet going viral, the mom simply requested that people call their congressional representatives to advocate for gun reform or support organizations like Everytown and Sandy Hook Promise.
They agreed with Cohen's initial assessment of the circumstances, calling the need for lockdowns "jarring" for students, educators, and families.