A few years ago I stood on a wet sloping rock and my foot slid down it. This slammed my big toe into the ground. It swelled up to twice its normal size and the end of my foot turned a wonderful shade of purple / blue. It was hard to walk for a week and was painful for a long time after.
I visited the doctor but it was a waste of time as he said there was nothing to be done. It might be broken, it might not. It would get better. Unless it was bent sideways he was not prepared to do anything. It did get better but doesn’t bend as much as the other one.
Basically, if your wife is really worried she could visit her GP but I suspect the outcome would be the same as I had. Ibuprofen and paracetamol will help with the pain. RICE (rest, ice, compression and elevation) will help it recover.