Sorry - I forgot to add that you will need to apply via VFS Global in Manila whether it is a fiance visa or a tourist visa.
For a fiance visa, I think you need to submit evidence that you have been together for at least two years.
She will need to make an appointment online and go there in person for an 'interview', which means they will spend less than five minutes checking all her documents, which ill then be sent to the British Consulate. You then have to wait 1-2 weeks for a decision.
f her application is refused (and the majority, it seems, are) you have no right to appeal and there is no way you can contact the British Consulate directly to discuss it.
It is very frustrating, as they will only say you have provided 'insufficient evidence' to grant the visa. They will not offer any advice as to what you should provide next time.
On our second application, we provided proof we had purchased a car in the Philippines, the receipt for the deposit on the house we were having built and a letter from our attorney in Manila, with his official seal on it, stating he was acting for us, but still she got turned down.