I recommend going to your PCP first, get a sleep study ordered. Many think that sleep apnea (OSA) is a disease found only in obese people. While OSA is more common in obesity, it can also be present in overweight and normal weight individuals. Thus, while losing weight may help, it may also not eliminate your risk for OSA.
Further, snoring does not equal sleep apnea, but they often go hand in hand.
If it is OSA, treatment could mean CPAP, oral appliance, Inspire implantable device, or surgery. A lot of great options that will help your wife sleep, but more importantly treat OSA. Most people don’t realize that OSA is a cardiovascular disease that can increase the risk for stroke and heart attack.
Good luck, you should be able to get this taken care of in short order.