I just had a thought, I can't remember if we sent the visa applicatoin to the British Embassy in Manila or the VFS who normally handle all visa applications initially, anyway their address is:
VFS Services Philippines Private Inc.
Phil-Axa Building, 2501-02,
1286 Sen. Gil Puyat Avenue, Corner Tindalo Street,
Makati City, Manila
Philippines.
It might be an idea to email VFS as well and ask them about it. One thing that has changed since we went through this process that might affect how you proceed with this is that visa applications are usually made in person to VFS because they now use biometrics (fingerscans and digital photographs) for all visa applications, but with regard to children, I don't know from what age this is required.
Something else that I just thought of is that when we had the visa fee managers cheque sent to us, we also had 2 passport type photos of my step-daughter sent at the same time because these need to be fixed to the application form.
Iain.