Harriet Hen nearly chicken stew

Harriet Hen nearly ended up as our neighbours' chicken stew last night because she flew over our wall into their garden. Unfortunately, Kay had already told us she was scared of chickens, so this was anything but welcome. However, when I suggested I might put a wire mesh fence along the wall to heighten it to prevent this happening again, I though Mike (Kay's husband) was going to make a stew out of me as well as Harriet. Conundrum. I don't want the hens confined to quarters all the time, although the run is big enough. They need some freedom to roam at leisure, but not next door!
Maybe I should clip their wings...