Ireland Baldwin says her cousin Hailey Bieber and her husband Justin Bieber "really complement each other".

Ireland Baldwin

Ireland Baldwin

The 23-year-old model - whose father, Alec Baldwin, is the brother of Hailey's father Stephen Baldwin - has heaped praise on the married couple, saying they've "helped each other grow", and are now "learning the ways of love and marriage" together.

Ireland said: "I think that they really complement each other. I think that they've really helped each other grow because before ... they started off having a lot of growing to do. They were just not ready. They were really young and they had a lot of growing to do and a lot of life to experience, and I think they both now are experiencing things together and learning the ways of love and marriage - not that I know those ways."

Although Hailey and the 'Love Yourself' hitmaker are already married - after having wed the same day they received their marriage license last year - they're still planning a larger ceremony for friends and family.

Ireland admits she isn't "really doing much" to help Hailey plan her big day, but said the 21-year-old model doesn't need it, because she's in "full wife mode now".

The beauty told Us Weekly magazine: "I am so happy for whatever they are deciding to do. I love Justin and I love Hailey. I love spending time with them. ... She's my little cousin, like my little baby, so I'm so excited to see her growth and her beautiful house that she's living in. She's full wife mode now, so I love it."

Previously, Hailey's older sister Alaia claimed she had no idea what was happening with the couple's wedding, as the pair kept changing their plans.

She said: "We will see. Who knows what their plans are. They're very up and down, so I just I'll be there at some point in a dress, in sweats - we don't know!"