Holders of a Philippine passport will need to apply for a visa.
Some applicants don’t need to pay any fee for their visa. These include non-EEA family members of EEA citizens.
You'll need to have proof of the family member relationship with the application and that you'll be travelling together.

The reason for free issue is down to Irelands interpretation of EU Freedom of Movement.

Take a look at the Irish legal Version here if you enjoy reading such EU gobbledygook.

Also here at the Irish guidelines for issuing visas to family members of EU citizens

(Just out of interest the UK equivalent is called the Family Permit)

EU Freedom of Movement allows EU citizens to freely travel between other EU member countries together with their 'Family Members'

Please do be aware that all citizens of non-EU countries, whether they require a visa or not, will be subjected to immigration 'control' at all entry points of Ireland.
Ireland is not part of the Schengen agreement and is also a separate country to the United Kingdom and so a separate visa is required.

Enjoy the reading