I'm so worried about my wife

My (24M) wife (24F) is overweight and she is 5'4 and 215 with a 45 waist. I love her a lot and she looks very pretty and I do get turned on with her curves. We have a son who is 2 and all I want in life is for my family to be happy and healthy but I'm so worried about her health. She does try to take care of herself and she does go to the gym mostly 3 to 4 times a week and she does eat healthy but just can't seem to lose weight. She has tried diets, drinks, anything but with no results. She had a baby 2 years ago and that caused her weight to balloon and does she get frustrated with her weight but she does try to do the best she can. I know she isn't perfect but she is perfect to me. My concern is her health and I want her to be around for me and our son. I'm so worried about her health and that she might leave us too soon. I know I'm probably worrying for nothing but I do want her to be healthy for me and our son.