Prayer to Saint Pancras (also known as Saint Pancratius):
"St. Pancras, pray for all teenagers that their faith might be as strong as yours, strong enough to lead them through all the trials of their life." (Personally, I would use "lives" because "teenagers" is plural...)
Saint Pancras is the patron saint of: against cramps against false witness against headaches against perjury Albano, Italy, diocese of children Iserlohn, Germany oaths Pontevico, Italy treaties
There are no special saints specifically assigned for daughters, but St. Pancras, and St. Nicholas of Myra are the patron saint of children.
As per the Patron Saint Index, William of York is a saint but not currently a patron saint.
a novena prayer is said for the patron saint in a parish.
There is no patron saint of bullying or against bullying.
Yes he is the patron saint of repented thieves.
There is no patron saint of children's health but the Infant of Prague is the patron saint of good health.
The patron saints of unborn children are Saint Joseph and Saint Gerard Majella.
Saint Nicholas of Myra is the patron saint of children, scholars and penitent thieves as well as a number of other causes. For a complete list of his patronages, click on this link.
As per the Patron Saints Index, the patron saints of unborn children are Saint Gerard Majella and Saint Joseph.
There are no patron saints of foster children but there are several patron saints of orphans: Agnes of Rome Aurelius of Cordoba Dagobert II Drogo Francex Xavier Cabrini Ivo of Kermartin Jerome Emiliani Joseph Kateri Tekakwitha Mamas Pulcheria
I see no specific saint for healing of children. However, St. Brigid of Ireland is considered as the patron saint of healers.