Does a u.s citizen minor need a visa to travel to philippines without her parents but with another

Under the Philippine Dept of Foreign Affairs website, here, hopefully, is the answer you are looking for:

Other Visa/Entry Requirements for Foreign Nationals:

* Minor children below 15 yrs. old Traveling to the Philippines Unaccompanied by or not Joining a Parent in the Philippines

A Waiver of Exclusion Ground (WEG) Under Section 29(a)(12) of the Philippine Immigration Act of 1940, as amended is required for children below 15 yrs. old who are traveling to the Philippines unaccompanied by or not joining his/her parent/s to the Philippines.

The WEG Order will be issued by the Bureau of Immigration (BI) at the port of entry upon submission by the WEG applicant of the following requirements:

1. Affidavit of consent by either parent or legally appointed guardian of the child, naming therein the person who will be accompanying the child to the Philippines and with whom the child will stay while in the country. The said Affidavit must be duly notarized by a local notary public or the consular officer at the Philippine Embassy or Consulate in the applicant???s country or residence;

2. Clear photocopy of the data page of the child???s passport;

3. Clear photocopy of the data page of the passport of the accompanying adult or guardian; and

4. Payment of immigration fees (currently, P3,120 per child).
Under the Philippine Dept of Foreign Affairs website, here, hopefully, is the answer you are looking for:

Other Visa/Entry Requirements for Foreign Nationals:

* Minor children below 15 yrs. old Traveling to the Philippines Unaccompanied by or not Joining a Parent in the Philippines

A Waiver of Exclusion Ground (WEG) Under Section 29(a)(12) of the Philippine Immigration Act of 1940, as amended is required for children below 15 yrs. old who are traveling to the Philippines unaccompanied by or not joining his/her parent/s to the Philippines.

The WEG Order will be issued by the Bureau of Immigration (BI) at the port of entry upon submission by the WEG applicant of the following requirements:

1. Affidavit of consent by either parent or legally appointed guardian of the child, naming therein the person who will be accompanying the child to the Philippines and with whom the child will stay while in the country. The said Affidavit must be duly notarized by a local notary public or the consular officer at the Philippine Embassy or Consulate in the applicant???s country or residence;

2. Clear photocopy of the data page of the child???s passport;

3. Clear photocopy of the data page of the passport of the accompanying adult or guardian; and

4. Payment of immigration fees (currently, P3,120 per child).