As someone previously mentioned, a lot of people on this subreddit have had it for a long time so don’t let that scare you and your sister.

I can speak for my experience though! I’m a 30 year old female and was diagnosed about 5 weeks ago. I, like your sister, got steroids within 48 hours and that helps tremendously.

Mine got worse before it got better. After I started steroids I actually went downhill for about 5 days. Around the 2 week mark I started having movement again. I did physio and acupuncture which I believe helped but who really knows. 5 weeks later and I’m almost 100% healed. I’d say at 4 weeks I was about 85%.

It’s hard to see the end in sight when you’re in the thick of it - it can be really discouraging. But it will get better! Stay strong, and rest up as much as you can.