If you use the search function, you will come across many posts, listing what is needed for a visitor visa, also it tells you that the success rate in obtaining it, is very slim, or none.....
Not many people get it. Try the fiance visa route, it may be more expensive, but if you have some proof of contact, ie, mail, chats, photos together, dosh in the bank, living accomodation, etc, you maight be able to swing it.
You don't have to get married within the time allowed, provided she goes back before it expires.
http://filipinaroses.com/search.php?searchid=375759
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Good luck.