well thats good, if your g/f has evidence, money transfers to her mom?
i've read some really

threads, not with filipinos but thai's who have had visa's refused on the grounds of "sole responsibility"... so get as much evidence as you can, so they will not refuse it first time.
bit different for me, stepson was 17, but still my wife got his father in america to write a letter stating he was happy for his son to be with his sister and mother in the uk and also a copy of his passport, i sent evidence that we had been sending money to his aunt,as she was looking after him, he was in his final years at school thats why he didn't come with his mom, pnb money transfer receipts, also we stated that when my wife applied for a spouse visa, that we stated we wanted her son to come and live with us when she was settled.
so try to get a letter off their bio dad, money transfer etc,