The military -- determined to stop Grace, 52, being named as the new vice president -- moved in on Wednesday, taking control of the country and signalling the imminent end of Mugabe's rule.
The source could not provide details of the talks, which appear to be aimed at a smooth and bloodless transition after the departure of Mugabe, who has led Zimbabwe since independence in 1980.
Nearly four decades after independence in 1980, many see him as power-obsessed and willing to unleash death squads, rig elections and trash the economy in the relentless pursuit of control.
Mugabe "indicated that he was confined to his home but said that he was fine," the South African government said in a statement that called for calm and restraint.
Following are key dates in Zimbabwean President Robert Mugabe's 37-year rule, one of the longest on the African continent.
Askar Zimbabwe dan tentera perisai menghalang jalan menuju ke pejabat kerajaan, parlimen dan mahkamah di tengah Harare, kata seorang saksi Reuters hari ini.
Soldiers and armored vehicles block roads to the main government offices, parliament and the courts in central Harare.
They deny Menk is divisive, but say the preacher had called for the use of 'inclusive' phrases such as 'Seasons Greetings' instead of 'Merry Christmas'.
Its ministry of home affairs says the two Islamist speakers have promoted divisive teachings unacceptable in Singapore’s multi-racial and multi-religious society.
Addressing the UN General Assembly, where reproaches of other leaders are generally less personal in tone, the 93-year-old veteran leader took Trump to task both on policy and appearance.
Mugabe tells tens of thousands of supporters at a rally in the town of Chinhoyi, in his home province, that doctors are surprised by his "strong bone system."
Menantu Robert Mugabe, Simba Chikore berada di Malaysia untuk memuktamadkan urusan pajakan untuk syarikat penerbangan milik kerajaan Air Zimbabwe.