From my experience 100k in Thai gfs bank and sponsorship letter from me saying I would cover accommodation/food was enough to get the visa. The main thing to prove is that your gf has sufficient ties to TH that would ensure she will return at the end of the trip. House, job, dependents are all positives that would work in her favour.
I got rejected on my last online report (and told to go to report in person) but before I went in I resubmitted it online just to try it and I got accepted the same day 🤷🏼‍♂️