Question FOSS software to convert photo to drawing

[kep55]

I want to write a book for our grandson using our cats for the images. I want to convert photographs to sketches / cartoons as are in most children's books. I tried on package that claimed to be free but left a blinkin' watermark on the results. I do not want online services for security reasons. I tried GIMP, Paint.net, fotor etc and they don't give me what a I want. Something that will give decent image that's obviously not a photo. Something closer to the pix in Charlotte's Web. Any ideas?