United Kingdom, Feb. 4 -- Jesy Nelson's experience of motherhood has been "so full-on".

The 34-year-old star's twin daughters, Ocean Jade and Story Monroe, have been diagnosed with SMA Type 1, a rare genetic condition that causes severe muscle weakness, and Jesy has now opened up about the challenges of raising her babies.

The pop star - who gave birth to her twins in May - told the Daily Mail: "Every day is so full-on, I can speak about it, but I'll never be able to explain how intense it is until you see it.

"There are a lot of medical things I have to do which I am still really struggling with; I'll be honest with you. I never expected that to be part of my life and it's tough.

"They're so tiny and I have to do things which I know ...