Suggestion on conflicts

We are happily married for 8 years. We have 1 kid of 4yr old son. We are trying for second kid since 1 year. My wife doesn’t want to go for any treatment to get 2nd kid. As per her, if it all it gonna happen then let it happen naturally. But I am very much anxious about it and get stressed out as we are not getting success. Will that be fine to pressurise wife to go for some treatment? Or it is not correct?