I am half filipino and have lived there for 8 years on and off, and have experienced a lot of the cultural clashes of life there and life in Australia. I just wanted to say that I hope all these posts don't make you too paranoid. I do think you should be cautious because it is common for cons there. But I just want to explain a bit on her side. It's true even to this day and age that it's common for boyfriends (even filipinos, especially if you are known to have money) to take the family out to eat. It's also common for people who lived overseas and are coming back to Philippines. My mum treats my relatives to dinner all the time when she visits there. But if you're short on cash just tell her you have enough to do it once or twice and if she loves you she'll be accepting. I suggest taking them to the mall (SM davao or the SM in manila if you are going there) and picking a restaurant there. If they suggest going to Makati a lot of places there are expensive.

They mention they're from Davao because it is one of the decent places in the Philippines because of an extremely strict mayor who is now running for president. It is a safe area and they even have 911. Manila is one of the worst places. But if you are really going there try visiting the Swagman hotel or other hotels that mostly cater to white people. The brother is probably coming because brothers are very protective. It is also common for people in the Phils to have parents protective of their daughters no matter what age. Even if they were in their 40s. Not every part of Philippines is Westernized. Just make sure that you are at least allowed to kiss her. Start with the cheeks and a few days later lips. If she doesn't want to it's most likely a red flag. Oh and at least she agreed to go with you there