Beyoncé's twins are ''amazing'', according to her mother Tina Knowles.

The 36-year-old singer gave birth to twins Rumi and Sir - whom she has with her rapper husband Jay-Z - in June this year, and her mother Tina has given fans an update on the tots, dubbing them as ''beautiful and healthy''.

She said: ''They are amazing. They're very young but they like to touch and they're adorable and just beautiful and healthy and I'm just so happy.''

The 63-year-old businesswoman also shared an update on Beyoncé and Jay-Z's five-year-old daughter Blue Ivy, who Tina says is ''doing amazing''.

Speaking to Us Weekly magazine, she said: ''She's doing amazing! She's a big sister and she feeds them and she's excited. And she feels responsible for them being here because she prayed for them.''

The news comes after it was previously reported that the 'Formation' hitmaker had initially been worried Blue Ivy would ''feel left out'' once the twins arrived, but was pleased when she proved to be an ''amazing'' big sister.

A source said: ''Beyoncé has been very busy with the newborns, but she's also been able to relax a bit. It's helped her that Blue has been such an amazing big sister.

''There was no need to worry because Blue is great. She takes her job as a big sister very seriously and helps out a lot.''

It was also previously reported that Beyoncé is ''full of energy'' since becoming a mother of three.

An insider claimed: ''Beyonce is amazing, she is clocking hardly any sleep right now, but she's full of energy and life!

''Most new moms of twins struggle to even function at this stage, but Beyonce is thriving.

''I mean, obviously it helps that she and Jay-Z have nannies and a bunch of staff, but she's still really hands on and she's breastfeeding, which means she's hardly getting a break rest wise - but then, Beyonce has always functioned best on less sleep than most of us mere mortals!''