These 9 celebrity sisters have said the most heart-warming things about each other

‘People ask if we argue, but from the moment she arrived in my life, she’s been my best friend and soulmate’

Whether it's the Olsen twins, the Hadids or the Williams family, celebrity sisters in particular are as thick as thieves - constant allies in the fast-paced world of Hollywood.

Besides, what good are luxury trips, private jets and couture wardrobes without a sister to share it all with?

Here are 9 of our favourite celebrity sister duos and the heart-warming things they have said about each other...

1. MARY-KATE AND ASHLEY OLSEN Ashley: ‘My sister is the most grounded, brutally honest and compassionate person…and my best friend.’ Mary-Kate: ‘We have been roommates our entire lives. We just bought a place together.’

2. GIGI AND BELLA HADID Bella: ‘We're definitely a lot more similar than people think. We have the same voice, the same mannerisms. Sometimes we'll finish each other's sentences, or we'll be the only people laughing.’ Gigi: ‘My sister is my little star, and I’m excited for her and proud of her. With her, I’m protective, but also I don’t want to be that sister who’s really pushy and thinks they know everything and making her feel like she doesn’t know what she’s doing. I’m trying to be that cool older sister and not the mom, but it’s hard.’

3. BEYONCÉ AND SOLANGE KNOWLES Beyoncé: ‘My sister taught me how to speak my mind.’ Solange: 'Now that she's become a mother, the way that she's able to balance that is so inspiring.'

4. CARA AND POPPY DELEVINGNE Poppy: ‘She's my baby sister - I could talk about her till I'm blue in the face. I know her name is on everyone's lips at the moment and I really couldn't be prouder of her. I'm so proud every single day.’ Cara: ‘Poppy believed in me more than I did, so for that I thank her.’

5. PENÉLOPE AND MONICA CRUZ Penélope: ‘It's funny actually, we very rarely clash. I guess we know each other so well, we work very well together, which is lucky! In fact, we often go away to look at inspiration and come up with creative content and ideas, and come back with the same thoughts.’ Monica: ‘Penélope and I never fight, we have a really, really good relationship. It makes me angry and sad when people ask if we argue because I can't imagine a family being any other way.’

6. SIENNA AND SAVANNAH MILLER Sienna: ‘There is no rivalry between us at all. We are incredibly close. Our parents got divorced when we were young. We were shipped about a bit. The thing that was consistent was “us” - we are partners in crime.’ Savannah: ‘People ask if we argue. But from the moment she arrived in my life, she’s been my best friend and soulmate.’

7. SUKI AND IMMY WATERHOUSE Immy: ‘Suki obviously looked incredible, the dress was amazing. She was my favourite, but I am a bit biased.’ Suki: ‘Quite a lot is happening for her at the moment. She's in LA at the moment and had to go three times this month as she's down to the last three of this massive film. It's huge, but she's not used to getting on a plane three times a month. I'm like 'babe you're going to have to get used to it, you'll have 10 a month. I try to guide her through it. I am kind of like her momager!’

8. ELLE AND DAKOTA FANNING Elle: ‘Dakota Fanning is my favourite actress. I’ve never worked with Dakota before in a movie. It’d be so cool to be on screen interacting with each other one day. It will happen, I’m just not sure when.’ Dakota: ‘Elle and I really don’t talk about acting very much, I don’t know if that will change as we get older. In terms of understanding what she’s doing with her life, we both have an understanding [of filmmaking] that not many people have. But I don’t think it’s made us closer. Our closeness has come from just being sisters.’

9. SERENA AND VENUS WILLIAMS Serena: ‘She’s the toughest player I ever played in my life, and the best person I know.’ Venus: ‘We don’t especially enjoy playing each other. It definitely doesn’t get easier.’