Imo. she's still young may be she realized that she can't commit yet and being a step mum of your children scared her or may be her auntie promised something to her that she can't say NO..may be a rich Japanese lol....who knows and only her knows what's going on.
i think that's the best way to move on and find someone new there's load of filipina out there (if you're still looking for pinay) sincere and worth your time and love. One thing for sure its not your lost its her lost...All the best