Gwen Stefani was ''devastated'' when her youngest son started school.

The No Doubt frontwoman - who has Kingston, 13, Zuma, 11, and five-year-old Apollo with ex-husband Gavin Rossdale - is thankful the youngster is settling in well at kindergarten but she was emotional having to say farewell to him.

She said: ''I got a baby in kindergarten now and that was devastating. But he's so excited and he's doing so well. I got junior high... God gave me all three boys. I've always been surrounded by boys.''

The 49-year-old singer is being kept busy with both her Las Vegas residency and as a coach on 'The Voice' and she admitted she's never felt more ''alive''.

She told 'Entertainment Tonight': ''I didn't expect to be doing [the Vegas show] and 'The Voice' at the same time. I just feel like I'm alive in a way I've never been before, because I have to be! Because doing both is a lot, and school started too.''

But Gwen feels particularly ''blessed'' to have her Las Vegas residency.

She said: ''I have so much fun doing that show. It's pretty magical and I feel really blessed to be doing the show.''

The 'Hollaback Girl' singer will be joined on 'The Voice' by her boyfriend Blake Shelton, John Legend and Kelly Clarkson and she thinks she'll face tough competition for contestants by the male panelists.

She said: ''Blake and I have similar tastes in voices.

''I think me and Blake hear a lot of the same kind of stuff and have the same kind of taste in voices. But I also think, John and I do. But Kelly and I don't.''