Hi @Tom-Burchell. I really like your illustrations. You have a very fun style! I like that Wix and Adobe Portfolio let you have rows of images instead of columns, something I've yet to figure out with Squarespace. I also really like that you've got the "heart" feature for you images.
A few thoughts after checking out your site.
I noticed that on each of the artwork tabs (Illustrations, Character Design and Picture Books) you have an "orphan" image at the bottom in its own row. Not a huge deal, but in my research I've found that it tends to look a little unfinished in the presentation of your portfolio. Reformatting the row so that there are no single images (or taking one image out) will make the whole illustration "block" a little more pleasing to the eye.
I like your "About" page and that it's more personal and casual (I do something similar in mine). The only thought I had while reading it is that the display font you use and is a little hard to read. That typeface is great for your tab titles, etc., but I'd consider a more readable font when typing long paragraphs, to keep the reader interested.
Other than that, it looks great! Hope this helps!
Josh