When asked if she gives the 'Iron Man' star any tips, Blythe said: "Oh, no. If anything, she gives it to me. She's brilliant. She's a really wonderful parent."
The 76-year-old Will & Grace alum went on to say Gwyneth - who is now married to Brad Falchuck - is "incredibly caring [and] incredibly patient" with her brood.
She explained: "When Moses was little, he would sit for an hour trying to figure out what he wanted in the toy store and I would think, 'Come on! We've got to go!' And Gwyneth would say, 'No, Mom.' [She's] very kind and patient."
Blythe lives "right around the corner" from Gwyneth and her family, and sees her grandchildren almost every day.
Meanwhile, the Goop founder recently claimed her mother had never wanted her to become an actress, as she was concerned about her daughter facing "rejection".
Gwyneth said: "[My mother] always said, "Oh, please don't be an actress."
"She was pleading with me to leverage my intellectual self more than my artistic self, and I think she was just trying to protect me from a lot of rejection. It can be a heartbreaking career."