According to NewsDay, Grace used to have security agents specifically assigned to her before she was kicked out of the ruling Zanu-PF party where she was the leader of the women's league.
The report said that Grace's security agents were "withdrawn progressively until Monday".
"She no longer has a team that is dedicated to her," a source was quoted as saying.
"Grace will largely depend on the team that is assigned to the former president. She can no longer determine how the aides operate, but will be an indirect beneficiary of her husband."
Presidential spokesperson, George Charamba could not confirm the development but said: "logically, I believe it would be expensive for the government to provide security to Chatunga [Mugabe's youngest child] now whenever he travels to America or decides to relocate there.
"I think the idea is that security details and other benefits are accrued to the principal [Mugabe].
"Other members now enjoy through the principal and not by virtue of their position or association."
This came just a few weeks after Mnangagwapromised to look after the soon-to-be-94-year-old Mugabe during his retirement.
Mnangagwa's government recently published regulations stating privileges owing to former presidents. They included a huge personal staff of cooks, waiters, gardeners and security officers, two houses, a fleet of cars and four international trips per year.