Kim and Sally Ledger will be hooking up with the "My Week With Marilyn" star and Phil Elverum, so they can put a face to the new man in their granddaughter Matilda's life.
The little girl was the product of Michelle's romance with the Australian actor, who died after suffering an accidental overdose 10 years ago.
Kim told Us Weekly magazine, "We're going to see her (Matilda) in New York next week. We'll be there a few days and see how she's grown. She seems to have grown pretty tall.
"(Michelle is) very private and I don't really like to make too many comments about her. But we are very happy (for her). We get to meet him (Elverum) as well."
Heath's dad was among those who publicly congratulated Michelle and musician Phil following their secret wedding earlier this year, and he thinks the actress has done a great job as a mom.
"We won't see the full effect of that for a number of years, I'm sure, but Michelle has done a great job as a single mom to bring her up," he beamed, explaining that his granddaughter looks just like Heath.
"She's got his beautiful flowing limbs, and a lot of his mannerisms, and his smile... It's quite incredible."
Michelle wasn't dating Heath at the time of his death - the couple split months before.