I'm not sure how much judgement I really want, but in my specific case, my evidence is just the usual sort of stuff you'd have from spending a month together back in January and another month now, with texts, calls, and the occasional money transfer, in between. There are tons of vacation pics, I met the folks and the kids, we toured around up north and down south so there are plane tickets from that. I'm heading back to Thailand very soon to spend a few more weeks together. Aside from the legal paperwork and a real marriage ceremony while I'm there I'm not sure what else we could do to prove that our intentions are genuine.
Other background info: I'm 53. I was married (to an American) for 20 years and then, more recently, a Thai woman for 1 year. No criminal issues, complaints, or anything like that. My current fiancé is 45, was married for a long time as well but is a widower. She has kids (10-19-25 who would not be coming to the US). She recently applied for a tourist visa but was turned down after the interview - which seems odd as she does have strong ties to Thailand and has travelled to Europe (and back) before. I don't know if that denied tourist visa is a problem, or my recent marriage (the K-1 for that was filed more than two years ago, the marriage ended last October, the I-485 and affidavit of support were withdrawn before adjustment of status), or the relatively short time we've been together. I do know, for certain, that I want to spend what's left of my life with her and that by 13 months from now we could have whatever proof of a (albeit long-distance) relationship anyone could possibly want.