No, these are not treated with a anti-bacterial agent. Sephora notes when its brushes are treated. They used to have a set that was for $69 and some of the platinum collection brushes are (the synthetic ones).

Yes.

Brushes are full size just like what you would get al a carte in the store. The width is a little smaller than the width of my hand when closed (4 inches maybe) and its about 8 inches long.

You could use it in a pinch, but a kabuki brush works better.

Slim Essential Brush Set , she will love it, soft bristles and non-irritating.

Th bruses are full size, but the handles are smaller.

Large brush is for all over finishing powder or bronzer. Angled bristled brush (second from left in photo) is for contoured application of blush, bronzer, or illuminating powder. I prefer a normal blush brush that's rounded (no angle). Middle brush is a large eye shadow brush for all over color. Smaller brush is for eyes, but for more detailed application such as highlighter under your brows. Far right brush is a retractable lip brush to use for applying gloss, lipstick, etc. It's excellent to use this sort of brush to line your lips using the pigment from a lip stick tube and then apply the lip stick per usual. You'll get a clean line.
This kit does not include any foundation or concealer brushes, which is what I think you want. If you use mineral or powder foundation, then you will want a large powder brush (like the one in this kit) and a large kabuki brush (very short handled brush with lots and lots of bristles for great blendability and coverage control). If you wear liquid foundation, then you want to use a large foundation brush which is flat and stiffer than a powder brush. Also buy the smaller version (sometimes called a concealer brush) so that you can apply concealer or your liquid foundation around eyes and nostrels.

Brushes are a microfiber, but "very, very" soft and they make applying all the different makeup a pleasure!!

The material of the brushes is microfiber. I don't know if that comes from animals, but hope it helps!

Water and mild soap will do fine, especially for synthetic hair. I have in my bathroom hand wash from Bath and body works (antibacterial, deep cleansing) and it works amazing. I make brushes wet, take some soap inside my hand and with circular motion swipe it. Than under luke warm water I see if all the color is gone. I squeeze gentle excess of the water with clean cloth or toilet paper, and let them flat dry (I place brushes on the counter so hair won't touch any surface). Make sure you always treat hair for the bottom, and always be delicate.I use it every week or so, depends how dirty brushes are. I also have Sephora spray cleaner and for quick clean I spray some in the paper towel, wipe towel around the brush and pull towards myself. It's antibacterial and dries within seconds. I read somewhere that the best cleanser are without any conditioners, they must have some alcohol and dry really fast. I hope I helped a bit!