To get a descent RMR sight, you’re looking at minimum $150, but typically $200-$400, so you will be well over $500. I definitely understand the want for an RMR sight, especially those who have trouble with their vision. I don’t know how much range time you guys plan on investing in, but I would focus on iron sights (I would upgrade to tritium night sights), and have your wife practice “point shooting.” Typically, in most self-defense situations, you don’t have time to get both hands perfectly on your pistol, get in your preferred stance, line up your sights on the threat, and shoot. Most of the time, the entire situation is over in a matter of seconds. I practice with iron sights all the time, but I make sure I spend at least 1/3rd of my range time “point shooting,” because the reality is, I will most likely not have time to line up my sights in a life or death situation (I’m not saying this is always true, just typically true). I have a red dot on my Mossberg 500, which I practice with all the time. I also practice with it off, and practice “point shooting” with it as well. I think people can get really hung up on sights. Based on statistics, most self-defense situations involve “point shooting,” and they occur in low light, which is why I have night sights (in the off chance I do have the ability to line up my sights). Just my $0.02.