Grace who spoke at a women's conference in Harare bragged that her daughter had completed traditional marriage formalities with boyfriend, Simba Chikore and that plans for what could be the country's version of a royal wedding were at an advanced stage, newzimbabwe.com said.
The First Lady also quashed reports in 2010 alleging that Bona had been raped in Singapore - where she was studying - after a student party.
Bona reportedly filed rape charges against two Tanzanian students the time. The two students who were put under police investigation however insisted that she had consensual sex with them, according to a Nehanda Radio report.
Earlier this year president Mugabe also spoke glowingly about Bona saying she was "very obedient" and "absolutely trustworthy" in an SABC interview.
Bona graduated with a Bachelor of Business Administration (Honours) in Accountancy degree from the University of Chan Tai Ho Hall in Hong Kong in 2011. She has also since attained another degree in banking and finance from Singapore and is set to graduate again in November next year.