Appearing on the talk show Live With Regis and Kelly, the Buffy the Vampire Slayer actress said: 'It's the greatest thing that ever happened to me. I don't know what I did or what purpose I had prior to having her in my life. I don't remember what my reasons were. Every moment of my day is spent thinking about her.'
Gellar has a two-year-old daughter called Charlotte with her husband, the I Know What You Did Last Summer actor Freddie Prinze Jr, 35. They have been together nearly 10 years.
'This trip is only the second time I have been away from her,' added the proud mum tearfully.
'It's sad,' she said.
Gellar, 34, is currently making her acting comeback by playing twin sisters in the TV show Ringer.
'I thought if I want to go back to work and still spend time with my child why don’t I play both lead characters? That was a really good idea,' she joked sarcastically.