Is Uber an option where you are? If your sister has sensory overload issues then driving could be a danger to her or others. Mobility is important but there are days I definitely would not be safe to drive. Living in a nice home in the suburbs could effectively become a beautiful prison if no reliable public or private transportation is nearby.

At the very least she needs to open her own bank account. Everyone needs their own spending money to even begin internalizing a budget. I personally found percentage based budgets to be very helpful and is what I teach my own son.

If she likes crafts could look at selling items online though a store like Etsy. If she likes games then could try to start streaming online via Twitch for pocket money.

If your sister is financially supported then before paid work I suggest looking into volunteer work. Will help build confidence completing tasks and working around others without the same pressure to provide immediate results and be profitable to the company.

Volunteering in areas where she has special interests would be ideal. If nothing local is feasible and she likes animals could try volunteering at a local animal shelter. If that does not work then you could organize a self volunteer outing like going to a public park or beach and spending time picking up trash. Gives a sense of immediate accomplishment and can visually see the impact that is made.

For education there should be many available online classes if in person remains a challenge. If pacing of regular school is a challenge then start out taking something self paced like via Coursera.