Nicky Hilton Rothschild is launching a jewellery line

She told WWD: "I have an obsession with personalization, customization, monogramming, and I've loved making customized gifts for my friends and family since I was a little girl.

"I used to work with a jeweller in Los Angeles. It would take a long time, it was very expensive....

"I've been doing shoes for the past few years, and that can be hard with sizing and gifting.

"But everyone loves jewellery, especially customized and personalised jewellery. I don't think there's a better gift than a one-of-a-kind, custom, bespoke piece of jewellery just for you. Nothing says 'I care' more."

Nicky aims to launch two collections a year and plans to expand beyond jewellery.

She said: "I definitely plan on expanding Theo Grace. I think it could be an incredible destination for people to come for all things personalised, and we could maybe expand from jewellery."

The model - who has Lily-Grace, eight, Theodora, seven, and Chasen, three, with husband James Rothschild - hopes her Theo Grace locket in particular becomes what the line is best known for.

She said: "Look at someone like Ralph Lauren, who, yes, everything he's touched [turned] to gold - the home market, children's, fragrance.

"I love designers that have flagship items, whether it's a Diane von Furstenberg wrap dress or Polo Ralph Lauren."

Theo Grace is named in honour of Nicky's daughters but because she expects to appeal to both male and female customers, she made an adjustment.

She explained: "I wanted to make sure the brand name was not too feminine."