Thanks for the additional information.
If you have a right to live the in the UK as an EEA National, your family may join you here. Your family is defined as:
- your spouse (husband or wife) or civil partner;
- any children or grandchildren of you, your spouse or your civil partner who are under 21 years of age or who are dependent on you; and
- the parents or grandparents of you, your spouse or your civil partner.
Other relatives (including extended family members such as brothers, sisters and cousins) do not have an automatic right to live in the UK. To be considered, the extended family member must be able to demonstrate that they are dependent on you.
If you and your partner are not married or in a civil partnership, you must be able to show that you are in a durable relationship with each other.
Thus, your partner will have to show that his sister is wholly dependant upon him whilst in the Phillipines. If she can prove this, her application has a reasonable prospect of success.
I hope this answers your question. If so, kidnly click accept.
If you wish to discuss, please feel free to ask further questions.