Hey, so how feasible is it for my character to self teach herself multiple languages (both spoken and written) and also creating an alphabet for her native language which has only ever been spoken?
Creating an alphabet for her native language would be pretty feasible, I think, especially if it has distinct sounds. It's not likely that it will lead to a universal standard of spelling, however, because there are likely to be many different accents and dialects within her native country and people won't agree on how to spell stuff. (This was the case with English before the printing press came along - even Shakespeare signed his name with multiple different spellings.)
Something else to think about is that if your character has been exposed to other writing systems, it's likely that she would just co-opt one of those for her language instead of creating something from scratch.
As for teaching herself multiple languages, that depends on a few factors. Could you share her reasons for wanting/needing to learn them, and the resources that she has on hand? The amount of languages and the timeframe (and your character's age when she learned the languages) will affect feasibility as well.
So my character picks up languages over the course of a couple hundred years and she learns them because she is the only person left of her native tribe, so if she wants to talk to anyone else she needs to learn their language. She doesn't really have much in the way of resources, just sort of picking things up from the people she meets. And she earns about five languages.
Okay, if she’s surrounded by people speaking another language, she’s almost certain to pick it up, especially if she’s around them longer than a few years. And with the timeframe you’ve given, it’s quite feasible for her to have learned quite a few languages, as long as she has a good memory and she keeps interacting with people. The more she interacts with the speakers of that language, the faster/better she’ll learn it.
Also, the more languages someone knows, the easier it is to pick up another one, so while the first couple of languages she learned might have been difficult for her, the subsequent ones would probably have been easier. In humans it’s easiest to pick up language to a fluent degree before puberty (I’m not sure what age that would correspond to for your character) but it’s not impossible afterward and if it’s out of necessity, like for your character, it would definitely happen.
Another thing to consider is that if there’s a language she hasn’t needed to use for several hundred years (especially if it’s not her native tongue), she’s likely to be a bit rusty if required to use it again.
Ok, thanks for the help. When she speaks to people in languages that aren't her first language she tends to use an older form of it from whatever era she learnt it, because like you said, languages change over time and she hasn't quite kept up with the changes. She also has a pretty good memory for words, as her only interaction to people as a child was through spoken words. And even though she has no one to speak her native language too, she still uses it a lot when learning new languages and sometimes to get out of talking to someone she doesn't like, she's also teaching it to one of her friends who in return helps her get better at interacting with people, because she spent about the first hundred years of her life not really encountering people.
That was probably a lot of extra information, but I just thought you might be interested, and I have lots of backstory for her.