After Brexit - Posting Products to UK

Does anyone have recent experience of sending things to the UK that have got to destination without extra import fees, courrier charges , or admin costs?

Niece A ordered birthday present from the Netherlands for Niece B just before Christmas. It got stuck somehow, and then company said they would no longer deliver to the UK. So Niece A had it delivered to me. And I now have to get it to Niece B in the UK.

Expensive (I think) brand new clothes…

Can I just send it via La Poste with CN22 as gift of fabric?