Oh dear :p We have LOTS of Sigyn variants that are not soft blondes :p
Mine is usually a small and chubby red head (fancast Nicola Coughlan), but we have MANY POC as fancasts too :3
One of the most popular is Angel Coulby, but there is also Zawe Ashton (though now that she's playing another character in the MCU, it's complicated XD), Dilraba Dimurat, Sophie Okonedo (for an older Sigyn), Golshifteh Farahani, Kirby Howell-Baptiste, Gratiela Brancusi, Philippa Soo, Jing Tian, Naomi Scott, Madeleine Mantock... and many others.
ALSO, some MALE Sigyn variants, but duh :p WHY NOT ;)
On point though : there is NOTHING WRONG WITH LIKING FLOWERS (or being basic? Is it basic to like flowers now? Then I am basic, sorry XD As far as my Sigyn variant is concerned, she likes flowers and baking ^^' Sorry to disappoint? ^^')
But yeah, the Sigyn fandom nowadays pictures her in very different ways - some still see her as a soft blonde (and there is nothing wrong with that :D <3, others see her as a brunette, as a red head, as a Valkyrie or as a healer, or as a Lady-in-waiting to Frigg, or as a Vanir Princess...
That's why the variant concept is so great and allows us all to imagine Sigyn however we'd like.
Our imagination is the limit :p And artists have a great time with this :3