The Houston Chronicle reported Friday that Peguero formerly was at Our Lady of St. John Catholic Church in Houston.
Family attorney John Sloan Jr. of Longview says the molestation allegations involve four relatives who are now adults, one man and three women.
The lawsuit filed Wednesday against the Archdiocese of Galveston-Houston seeks unspecified compensation.
Archdiocese spokeswoman Jenny Faber says an attorney for the family complained about Peguero in 2007. Church-sponsored counseling was offered, but the plaintiffs declined. Faber had no further comment.