I went to the gun counter instinctively - shit like Mace is a propellant and dangerous/hurts really bad/offensive weapon. Made sense to look behind the counter.
They have a Mace/Pepper spray on a blister pack hanging in the....
wait for it
I was looking for something for my daughter in college when they had a warning about some weirdo seen moving around inside dorms after hours. Hadn't hurt anybody yet, but just behaving in troubling ways.
Anyhow, Dick's has a personal defense spray x3 - it is part Mace, part Pepper spray, and part Tear gas. We settled on that one.
DO NOT, I repeat, DO NOT let her buy just any off-the-shelf pepper spray from your local hunting store (Bass Pro, Cabelas, etc) or Wally world! Most pepper sprays you get from those types of places is SHIT, unreliable, and nowhere near as powerful as it should be to prevent someone from pushing through the pain and doing harm. Go with a place like Fox Labs or similar. They are one of the premiere pepper spray producers and many federal agencies trust their product as well. They are pretty nice people and even sent me a free extra can for a military discount. I got the 5.3 in spray pattern.