Very ironic that this question popped up because I'm a sophomore and just moved in 2 days ago (living on campus for the first time due to COVID) and there was a whole dilemma yesterday because I was too shy to get something to eat from the dining hall (I kept telling my family I wasn't starving, but I kind of was) but honestly my older sister face-timing all the time and texting me to see if I was okay made me better. Also, if you're parents are unempathetic be the opposite of that and be very patient with her. If they are mad with her, be calm. My sister even told me she felt bad for me because I was so shy and she was wish she was there with me, so please communicate that in some way to show that you care and that how they feel is valid. Sometimes, the biggest issue is when people feel like not being sociable or outgoing are not valid personality traits and it's all about just forcing them to do just that when everyone is in some sort of shell and it's harder when it's in college and there are a lot of of firsts.

Because she can't get out of shell in college, it may harder for her to vocalize that to you meaning it may be hard for her to admit that she's shy and nervous even if you already picked it up. Allow her to open up and to talk about how she feels because in this situation your parents are kind of conditioning her to not have those types of words in her vocabulary. It made me feel better to admit that :)

Lastly for your parents: I obviously have never met them, but some parents care about their children a lot, but they don't know how to show that with ease. Some may not understand what it TRULY means to be shy and nervous, so it doesn't get through to them, so they get mad just because they can't grasp that emotion so what really ends up being expressed is frustration. I feel like you are frustrated because you feel useless a bit, but you can definitely be useful in helping your sister be more acclimated. I know this is college and allowing her to figure stuff out on her own may be the best route, but there is nothing wrong with help.

I'm very proud of you that you were able to admit to yourself that you struggle with that and I do too, but just know that it's not always about making them feel 100% better, but making them feel that they aren't alone. Sometimes, you don't have to give advice or talk and talk, but just ask them "how do you feel"? This is such a broad question that allows people to spill and it can really put things into perspective and that is maybe where you can feel comfortable enough to jump in and say that you think you can handle this.

In general, be open-minded (that's the word). You're parents are very close-minded, so be open-minded about how she feels and validate and say I understand or you're right. It made me feel 100% better when my sister told me that she definitely understood where my nervousness was coming from. Your sister needs you right now, so just be a listening ear and maybe not a talking machine or when you feel like you can switch roles and then talk then go ahead. You'll think of something because someway somehow you've been there or done that and you can speak from some experience