How did this dino survive till Jurassic World: Fallen Kingdom?
It is made abundantly clear throughout the Jurassic Park franchise that raptors are social creatures. That presumably means that like dolphins, they hunt in packs and rely on the companionship of other dinos/aquatic mammals.
In real life, animals can be social to different degrees. Humans, for example, are most healthy and happy when with access to other humans, but are still able to obtain food by themselves (we're omnivores, we have choices...) Some animals are pack hunters though, such as wolves, and rely very heavily on the pack factor for obtaining food. Lone wolves, of course, are a thing, but they don't tend to live that long because they have difficulty killing their favored prey -- large ungulates. Also, they have less defense against other enemy wolves and predators.
Velociraptors are seen hunting in packs in several of the Jurassic Park films. That's how they supposedly obtain food.
But in Fallen Kingdom, Blue is still alive, apparently having survived for half a decade as a solitary raptor. At the end of the movie, she is seen galavanting about through a residential area -- as a solitary raptor.
How is this possible? How can she obtain food/safety without numbers? Obviously, there are no guarantees about her survival after Fallen Kingdom, but the plot does drop hints that dinos probably will take over the earth (maybe) and you'd expect raptors...
I learned something new about social animals: Apparently, even certain very social species such as wolves who ordinarily choose to hunt in packs, may survive as individuals. While this is far from ideal for the animals, they are quite able to survive and adapt, causing the velociraptor's survival in solitude to be perfectly explainable.