Since McDermott, 43, has been home from the hospital, children Liam, 3, and Stella, 2, are having to adjust to seeing their injured father, who is healing from a punctured lung.
"It’s hard," Spelling, 37, told PEOPLE at Dairy Queen's Turn Blizzards Into Smiles event Friday in Los Angeles. "It's hard because Liam's a daddy's boy, so he wants Dean to pick him up and we have to explain that daddy's sick, that he's hurt, so he can't get up."
Spelling also says there's no way to predict how long before her husband is back to normal until he begins rehab. "[Dean] gets up for a short walk every day, but it's hard for him."
Reporting by MELODY CHIU