My sister is planning on having her baby baptized soon. She has asked my brother and his wife to be godparents, but they are both divorced Catholics and neither got their annulments before their remarriage and have yet to apply for them. Will the baptism be valid?
Code of Canon Law (CIC) requires sponsors (godparents) be provided for infant baptism “insofar as possible” (CIC 872) - they are not an absolute requirement for valid baptism.
To be a godparent a person must be one “who leads a life of faith in keeping with the function to be taken on” (CIC 874.3). Your brother and his “wife” may not qualify due to their irregular marriage.
In such a case the sponsorship may be invalid but not the baptism.