So I am wanting a name for a strong female character that can be shortened as she evolves. I have read a few stories that use this technic, and I feel it helps distinguish the new journey for the character and distinguish who they use to be vs who they are becoming. for example, anastasia --> ana, beatrice --> tris
There’s a lot of female names that can be shortened, it all depends what sort of name you want to start with (classic, frilly, rare, popular) and what sort of nickname you want to end up with (boyish, spunky, unusual)
There are plenty of options, depending on time period, meaning, etc. Since you used [name]Anastasia[/name], I can assume you like more traditional, classical names, so I’ll give you a few that I know well:
[name]Katherine[/name] (or [name]Katerina[/name], [name]Ekaterina[/name] both used in Russian or European): [name]Kate[/name], [name]Kit[/name], [name]Kathy[/name], [name]Katy[/name]