congrats. But almost 100% of the time I see this bad situation happen it's with a bk or Pattaya girl that's too young and wild. My wife is 2 years younger than me and from buriram.yes she deals with my shit but I try not to give too much hell
you can do the paperwork yourself but your best option is to hire a reputable service or attorney in Thailand to assist you in taking care of the logistics that need be there. They will help you prepare all the paperwork and assist your fiance through the interview process to obtain the Visa. Most of them will accommodate travel to and from the embassy in Bangkok. It will cost in between 1500 and 3,000 USD. But you're still going to have to educate yourself quite a bit, there's a ton of help on YouTube
It's a commitment definitely. In the long term she will have to stay here for about 3 to 5 years until she can obtain her citizenship and then you're both free to move back and forth between the two countries. Getting a marriage visa for Thailand is very easy for you. I've known people that have done it in less than 2 weeks.