Blue Ivy Carter is "so excited" by the prospect of becoming a big sister.
Beyonce, Blue and Jay Z
The five-year-old daughter of Beyonce and Jay Z cannot wait to have two new playmates arrive in their family home later in the year.
A source said: "Blue is so excited to be a big sister!"
Beyonce and Jay Z are also thrilled to be expecting twins after trying to conceive for so long.
The insider told Us Weekly: "They are ecstatic. They have been trying for a long time and now to be blessed with twins they are so over the moon. It's even better than they wished for."
The couple announced their happy news on Wednesday (01.02.17) via Beyonce's Instagram account.
Alongside a photograph of Beyonce proudly displaying her baby bump, a message wrote: "We would like to share our love and happiness. We have been blessed two times over. We are incredibly grateful that our family will be growing by two, and we thank you for your well wishes. - The Carters."
Beyonce and Jay Z - who got married in 2008 - have both previously spoken about their desire to have more children in the future.
The rap star quipped back in 2013: "[I want] a little basketball team."
And Beyonce echoed that sentiment in the same year, revealing she wanted Blue Ivy to have "some company".
The 'Halo' hitmaker said: "I would like more children. I think my daughter needs some company. I definitely love being big sister [to Solange Knowles] ... I am very protective.
"I just want to make sure that [Blue Ivy] can have a healthy, safe, normal life. In the back of my mind, she's my priority. And life is completely different now."
Meanwhile, Beyonce's post about her pregnancy has already become the most-liked picture on Instagram.
The likes on the singer's photograph smashed the record set by Selena Gomez, who garnered 6,315,187 likes with a picture of her drinking a can of Coca-Cola.