Hi there Trevor, welcome here.

Sorry to hear about the refusal. I understand the disappointment for you both.
The refusal reasons given are really the most common.
Tourist visa is very very tricky to secure.
Firstly, I must tell you there is no appeal procedure available. That's only for family visit.

You would need to re-apply and be sure that the application completley countered ALL the reasons for refusal.
A 3 month tourist visa will require very significant financial resources.
Sorry not to have all details of your application, but in addition to adequate funds for the TOURIST duration the applicant needs to convince to ECO of compelling reasons to return home. Sadly children are not always considered as such.

You can of course apply again. In principle the second application will be considered on it's own merits. The visa is not too expensive so may be well worth the effort and cost.
The application MUST be fully compliant with requirements and the sponsors letter must also be well supported with full documentation (ie Passport ID, Pay slips, P60's, Bank statements etc, Accomodation details with overcrowding, what will be done during the 3 months etc) Remember, even the request is for 2 weeks the visa will be valid for 6 months.
Then MOST IMPORTANT the applicant (your g/f) MUST convince the ECO she will actually return to Pinas. This often means not making any mention of any b/f in UK.
To be honest this is probably the most key issue.
Letters from employers are key etc

Sorry if my words sound harsh, that's not intended. Just trying to help you.
Maybe better for you to visit Pinas than she will visit UK unless you can pin down everything securely for the application.

Take care, God Bless and good luck