Don't know about a chessboard that shows ALL the squares that can be attacked. Though I do know of several ways that your wife could potentially improve her board vision at an intuitive level. Also, there are plenty of sites & smart chess boards that have a "show threats" option of some sort, as well as an option to draw your own arrows & highlight your own squares (including chess.com).
Hope that answers your question to some extent.
Hi everyone. I’m trying to help my wife learn chess, but she’s having trouble visualizing the squares opponents can potentially attack on any given turn. Are there any chess apps or games that have a built-in threat/heat map function? In other words, they should highlight squares that can be attacked on any given turn.