Artwork by  Illuminatii

One of Kate's plot points in her unwritten story is that, in her early teens, she started manifesting a curse that caused her to be temporarily displaced forward or backwards in time, seemingly at random, for days up to months at a time, often for longer than she is actually gone in the present. This means that there's plenty of opportunities for her to meet herself, though normally she avoids it. In this case, there's three of her at once: 17 year old Kate, early 20s Kate (this being the first iteration of that outfit/design for her), and late 20s Kate.

Teen Kate is still a trainer out looking for adventure. Early 20s Kate is a ranger who's been through whatever basic military service or the National Guard equivalent is in Unova, and late 20s Kate is not-quite-yet a mom, but is a badass who knows damn well what she's capable of.