Great question! While this technology might be possible in the New Heartland, they are a very utilitarian/resource controlled society at the end of the day. So for your character to have cosmetic enhancements to have animalistic, they would need to be more plastic surgery based. There is some form of gene augmentation, but the research is mostly from the pre-war world and that research was focused on “corrective” gene therapy to prevent any physiological conditions they could. Feline ears and tail would fall more among the cosmetic surgery side.
As for how your character would be able to have that kind of procedure done in the year 2142… hmm…
Culturally, even the elites of the New Heartland would be vindicated if they were using medical resources to get cosmetic surgeries done. Even though they can technically do whatever they want, the government is very bent on getting everyone to follow the no-nonsense and passion principles of their society. So I suppose the only real way would probably be if your character came from outside New Heartland, which would introduce a whole new host of discussion. Hope this was able to illuminate a bit!
Well, I was planning on my character being an orphan. Do you think it would be possible for her parents to have taken part in the genetic modification, and it simply passed to her? Or perhaps her parents were from outside the state, and got caught but not her?
If not, it's fine! Just trying to come up with an easy solution first, before getting into the nitty gritty of everything.