Extreme smell sensitivity -- what can help?

My 4yo has a very sensitive nose and is intensely bothered by certain smells. The one that comes up most often is bare feet (including her own): she couldn't sleep at school until she was moved farther from kids who sleep without socks, and she hates circle time because some kids go barefoot then. It feels like her instinctive reaction to smells she finds unpleasant (feet, breath, cooking smells) is to feel attacked by the person making them—so, not great for social interactions. It is much like my autistic older child reacts to sounds, and I do wonder if she is autistic also. I feel sure she has a genuine sensory difference. (She also loves smells I find aversive, like chemical smells and fishy catfood.)

She is going to kindergarten next year (BUSD), and I’m hoping this will be less of a problem there (maybe kids keep their socks on anyway?)—but if it does come up, I’m worried about how it will affect her socially.

If anyone has experience with this kind of sensitivity, what have you found that helped? We are on a waiting list for Full Circle OT and I'm hoping they can help with strategies for either decreasing sensitivity or managing the unpleasant experience, but I'd love to have some ideas in the meantime!