i guess my other option is to keep a round chambered, so all she has to do is flip the safety off on the AR. The dbl action trigger on the sig won’t work but I bet the glock trigger might. She probably wouldn’t be able to get many shots off but then it wouldnt take many with a .45.
What I would recommend is looking around your local area for a gun class for ladies, taught by a lady. They can often times provide the right opportunity to try different kinds of guns and find one she can operate. You might be able to find a recommendation at your local gun shop.