Illegitimate Child custody

Hi good day po. Ask ko lang po kung ano po pwede gawin kasi yung daughter po ng sister ko nasa kanyang ama po. Pareho po sila nag tatrabaho abroad so yung bata po yung nanay ng ex partner niya yung nag aalaga. Hinihingan po yung kapatid ko ng pera nung ex partner niya. Pag di daw po magbibigay yung sister ko tatanggalan daw po nila ng karapatan yung sister ko sa bata. Eh yung lalaki po kilala namin na drug user. Paano po kaya pwede namin gawin?. May laban po ba yung sister ko sa pananakot nung ex niya na tanggalan siya ng karapatan sa bata? And sino po ba yung mas may karapatan sa bata?.. Thanks po..sana po masagot yung mga tanong ko. It would be a great help. Thanks po.

(My Tagalog is bad so I understood only some, so I answer in general.)

When the child is younger than 7, then the mother get the custody alone automaticly. except if a court find her not fit as a PARENT. (It's risk drug adiction can be found a reason for that.)

Undepending of who get the custody, the other parent have visitation rights (as long as not have behaved to bad so it become risk for the child).

Undepending of who have the custody, BOTH parents are suppoused to support the child finansialy.

Above is valid as long as no documents are signed to make OTHER agreement volontaringly, so DON'T sign such. Specialy DON'T sigh adoption agreement if wanting to keep contact and the adoption agreement include that IN WRITING including stay living close enough to make visits possible for poor.
In common adoption the child can even leave the Philippines WITHOUT the other parent need to agree, but without adoption the other parent can stop such leaving by not agree.