[9] Decker has written legislation[citation needed] to ban toxic chemicals in firefighter protective gear, which was signed into law.

[10] As lead House negotiator,[11] Decker developed legislation to create resources on maternal health, which was signed by the Governor in August 2024.

[12][13] In 2018, Decker co-authored legislation aimed at closing a loophole in Massachusetts law to ensure that police officers cannot claim consensual sexual conduct with individuals in their custody.

[19] She received the endorsements of Governor Maura Healey, Senator Ed Markey, and local Congressional Representatives Katherine Clark and Ayanna Pressley.

In 2022, a non-binding ballot question organized by her later political opponent[3] was presented to voters in her district, asking whether their representative should support changes to House rules to make each legislator's committee vote available on the Legislature's website.

[21] In 2020, the Massachusetts Department of Conservation and Recreation (DCR) expanded Riverbend Park along Memorial Drive in Cambridge to include Saturdays.

[31] After considerable public debate and a Cambridge City Council vote in support of expanded hours,[32] the DCR limited the park space to Sundays only in April 2023.

In a March 25 email, Rebecca Tepper, Secretary of the Executive Office of Energy and Environmental Affairs, noted a "falling out" between Decker and fellow Representative Mike Connolly, who supported the extended closures.

[4] Decker has not commented on the nature of the employment since it was revealed through a public records request in 2024,[4] brushing off criticism about the second job and explaining that she is producing sufficiently for her constituents.