hello
@SigerHolmes and welcome
it's often the case that the person someone is concerned about doesn't see the need to see their GP
so I agree with nitram ... maybe keep a journal for a couple of weeks noting any issues that come up, so you have specifics for her GP, and have a chat with the GP yourself ... they may not act or feel able to discuss your wife's health with you, but they do have to record your concerns, and they may be proactive
other things can cause similar symptoms to dementia, such as stress, depression and deficiency in vitamin B12 ... would your wife go with you to see the GP because YOU want to discuss taking some supplements recommended for older folk and you'd like her company/moral support - if you'd previously forewarned your GP, they could maybe use that as a way to apparently talk to you both