As Grand Chief, she worked to address the reputation of the AMC following Dumas' tenure, negotiating water and land claims for Manitoba First Nations, working towards the return of the Sioux Valley Dakota Nation to the AMC, and advocating for a landfill search for the victims of the 2022 Winnipeg serial killings.

On September 6, 2024, Merrick was addressing a press conference outside the Manitoba Law Courts in Winnipeg, following the acquittal of the corrections officer involved in the death of William Ahmo.

[4] While speaking to the media on a separate issue regarding the Children's Special Allowance,[5] announced the previous day, she suddenly collapsed.

[13] Among the candidates vying for the position were Sheila North, Eugene Eastman, Jennifer Flett, Cora Morgan and Darrell N.

[7] Merrick was a prominent voice in calling for a landfill search for the victims of the 2022 Winnipeg serial killings remains,[14] with Niigaan Sinclair writing for the Winnipeg Free Press describing Merrick as the "primary political voice demanding a search of the Prairie Green landfill".

[10] Merrick collapsed suddenly on September 6, 2024, while talking with reporters outside of the Winnipeg law courts regarding the acquittal of corrections officer Robert Jeffrey Morden following the death of William Ahmo.

[1][14][16] In response to her death, Premier of Manitoba Wab Kinew stated: "She approached her work with joy, compassion, thoughtfulness and a spirituality that was grounded in the belief that we are all equal in the eyes of the Creator and that we all deserve to live a good life".

[3][9] Prime Minister of Canada Justin Trudeau stated she was "a relentless and incredibly effective advocate for First Nations peoples, especially for those most vulnerable.

[3][9] Mayor of Winnipeg Scott Gillingham described Merrick's death as a "huge loss" and that "I will only hold her in the highest regard.

"[3] Manitoba Métis Federation president David Chartrand described her as "a consummate professional, a strong communicator and a passionate advocate for her people — she died as she lived, working tirelessly for the causes she cared about.

Her spirit and legacy is an example to us all"[3][9] and MP Niki Ashton, who represents the Pimicikamak Cree Nation in the Parliament of Canada, described Merrick as an "inspiration" who led with "compassion, determination and courage.

[14][11] Merrick's body was laid in state in the Manitoba Legislative Building on September 11, 2024, only the sixth person and first woman to have received the honour, preceded by Elijah Harper.