"You can say I'm extremely happy, Amal's a lovely girl," Nina Clooney revealed.
Amal Alamuddin and George Clooney in October 2013
The news of George and Amal's engagement came several days after the couple were spotted dining at sushi restaurant Nobu, where Amal was seen flashing a "huge ring" on her ring finger.
The 74-year-old added: "I like her very much.
SAY HELLO! TO GEORGE CLOONEY'S NEW FIANCÉ AMAL ALAMUDDIN
"We weren’t at all surprised when they told us they were engaged, and we couldn’t be happier for them. On an intellectual level, they are equals. That is very important to him. Amal’s world couldn’t be more different from the Hollywood lifestyle."
When asked by the MailOnline if Amal was very similar to the other girl’s George has dated, she replied resoundingly with: "Heavens, no! She’s a lawyer, she is brilliant, she is a very bright woman and at the very top of her career. They also share a sense of fun, a sense of humour and they are both very caring people."
Amal's firm, Doughty Street Chambers, who are representing the Wikileaks founder Julian Assange, also released a statement confirming the engagement.
"The barristers and staff of Doughty Street Chambers offer their best wishes and congratulations to Ms. Amal Alamuddin, a member of Chambers, and Mr. George Clooney on their engagement to be married," the statement read.
Robin Jackson, chief executive of Amal's law firm, said: "She brings a bright light to everything she is involved in, and I am so delighted at her happy news."
Amal is an adviser to former UN Secretary general Kofi Annan and is also the special envoy to Syria, and she reportedly played hard to get by using her strategic planning skills.
Amal in 2012 at a press conference in support of imprisoned former Ukrainian leader Yulia Tymoshenko
A source revealed that George apparently asked her out for dinner and she told him twice that she was too busy before accepting the third time.
"She was operating on the lines of "treat ‘em mean, keep 'em keen" and clearly it worked. Clooney was beguiled by her and she had the upper hand", said the source.
The source continued: "What he likes about her is that she treats him normally. He’s so used to being fawned over that it’s refreshing for him."