The 'Single Ladies (Put A Ring On It)' hitmaker is due to headline the world-famous music festival on June 26 and Emily Eavis says she booked the US singer in order to keep the line-up diverse.
Emily said: "We are really keen to keep the line-up as diverse as possible. It's always been that way. We really want the people who are the masters of their fields, and that's what she is.
"I went to see her live last year and was blown away by the might of the show. She has such soul, an amazing voice with an incredible, all-female band. She knows how to deliver live, and she packs a big punch - it's gonna explode! And she is, I believe, the first female solo artist to headline, so it's a big moment for us."
Coldplay have also been announced as one of the headliners of this year's festival - which takes place at Worthy Farm, Somerset, South West England - and Emily admits she and her father, co-organiser Michael Eavis, feel "lucky" to have them return to headline the event, six years after they last topped the bill.
She told GlastonburyFestivals.co.uk: "We were really lucky to get them. It's been a while since they came and played here, so I think this will be a big one. They're one of the great Glastonbury bands, that really get what we're about and that have supported us through some tricky times."
Glastonbury 2011 takes place between June 24-26.