Do these fit smaller women?

Yes. I bought these for my 13yr old grand daughter for when she goes horseback riding in cold weather. She's about 5'3", and slim. In fact, these gaiters probably wouldn't fit a large person at all, though they are pretty stretchy. They are rather thin material, but they do break the wind on her neck and face, which is what she wanted. Also, the gaiter isn't bulky when she pulls it down around her neck, which she likes.

Yes, came as a set. Extremely thin. My family didn't use them.

What about men with full beards

Works well with beards as it has length and doesn't fit snuggly around the neck. My son loves it and he has a beard.

My dads nose gets very stuffy after he does the lawn. Will this protect his nose against the dust, pollen and dirt from mowing and edging the lawn?

The issue with pollen and other debri is the size of the particle. The gater will stop some but the pore size in the gater is still very large, greater that 200 micron. The things you want to stop are between 10 and 100 micron. So a surgical mask or even a painters mask worn under the gater are recomended to stop everything that is effecting your dad. To give you a reference, when the light shaft comes through the windo and you can see floating dust particles those are mostly greater than 100 micron. Young human eyes can see particles to about 75 micron.