St. Peter's Daughter

[Shin]

Today is the Feast of St. Petronilla, Virgin

In the Roman Martyrology we read for today the 31st,

'St. Petronilla, Virgin, daughter of the blessed apostle Peter, who refused to marry the nobleman Flaccus. Given three days for consideration, she spent them in fasting and prayer. On the third day, having received Christ sacramentally, she gave up her spirit.'

The Liber Pontificalis describes the translation of the saint's remains from the cemetery to a mausoleum in St. Peter's Basilica by Pope Paul I. It holds that "the carving of the letters [on the sarcophagus] could be identified as being engraved by St. Peter's own hand out of love for his sweetest child."

[CyrilSebastian]

I came across this topic and learned something new.   
Peter was the father of Petronilla.   
Usually we only hear about Peter's mother-in-law mentioned.