Alyson Hannigan has revealed that she frequently turns to Sarah Michelle Gellar for advice on motherhood.
The 51-year-old star has been married to Buffy the Vampire Slayer co-star Alexis Denisof, 59, since 2003 and together they are parents to daughters Satyana, 16, and Keeva, 12.
Meanwhile Gellar, 48, has been married to Freddie Prinze Jr, 49, since 2002 and they are parents to Charlotte, 15, and Rocky, 12.
Hannigan and Gellar have been raising awareness about meningitis vaccinations and were asked by PEOPLE magazine if they lean on each other for parental tips.
Hannigan shared, "I always usually call (Sarah) for the advice," and added that "it was nice to have a role reversal for this once," explaining that Gellar had asked her for advice on vaccines for her kids.
Buffy Summers star Gellar then insisted "there's been way more than once" that she turned to her former co-star for advice.
Warning of the dangers of meningitis, Hannigan said, "It's an uncommon, but a very serious illness that can, within 24 hours sometimes, have very serious consequences, even death."
And explaining their campaign to raise awareness, Gellar added, "I think ultimately the message we want to get across is knowledge is power."
Buffy ran for seven seasons and 144 episodes from 1997 until 2003 and plans for a revival series are underway with Gellar returning to her iconic role and executive producing the series.
Last week, Star Wars actress Ryan Kiera Armstrong was cast in the lead role, while Marvel's Eternals director Chloé Zhao will be directing the pilot episode.