"It is important for Marie and her children to get back to a routine that is comfortable for all of them and be together as much as possible," a close friend tells PEOPLE. "They're all together and doing their best to return to work and school."
All 720 tickets for the show at the Flamingo Las Vegas were snapped up. The hit show took a temporary break after Michael committed suicide on Feb. 26 in Los Angeles.
"The fans have been so wonderfully supportive of her throughout this tragic time and thanks to them and the love and support of her family and faith, Marie is just trying to get through this very sad time," the family friend says.
It wasn't known how – or whether – Osmond or her brother Donny would address Michael's death, though the 90-minute show does feature several portions of ad-libbing.
A Flamingo Las Vegas source says the hotel has been flooded with requests from people inquiring on where to send flowers and well wishes. "Everyone has really been rooting for her," the source says.
Flamingo Las Vegas announced that there will be five extra show dates from April 13-17 to accommodate those who had tickets to recently canceled shows.
Additional reporting by MARK GRAY