I will very much want to wish you a blissful relationship with yr viet gal. But you are not there in Vietnam most of the time (although 13 visits in 2 years), its really risky to trust her up to 95%. I may not sound very positive but due to all the things i have seen in Vietnam, i am seriously very careful when dealing with them. No matter what, you know what you want. I will think that it will be a good idea to get yr brother to get a local person to tail yr gal for around a month before you seriously want to committ yr next few decades to her