Alyson Hannigan, who recently became a mom again to her 7-month-old daughter Keeva Jane, revealed she was worried there would be sibling rivalry between the new baby and her 3-year-old daughter Satyana.

"We did a lot of making it a really big deal, like, ‘You get to be a big sister!’" Hannigan, who grew up an only child, told People.

"When the baby arrived, we had her give her big sister a big play structure in the backyard. It was a gift from the baby to her big sister and [Satyana] loves it," she said.

Hannigan says there's nothing but love between the two sisters and there hasn't been a moment where she and her husband Alexis Denisof suspected sibling rivalry.

"The other day [Satyana] was hugging [Keeva] so hard I was like, ‘I think her head might pop off.’ I don’t want to be like, ‘Ooh!’ because I don’t want her to have a complex about her sister. But I’m like, ‘Oh you know, I don’t know if she can really breathe right now! That might just be a little too hard,’ and Keeva’s just as happy as [can be]. It’s so great," the 38-year-old actress explained.

Hannigan is known for her previous role on Buffy the Vampire Slayer as well as her current role on How I Met Your Mother, but she couldn't be happier with her greatest role to date, being a mother.

"[Being a mother] has changed me in every way because my life is so much greater. It filled a void I never knew was there -- it's the most amazing experience of my life. I just feel so blessed to get to be on this journey, to be a mommy," she told Us Weekly.