Agnes Sorel mysteries

I am trying to establish her family a little more solidly and to be =
honest I am hitting brick walls.

Agnes Sorel was a daughter of Jean Soreau and Catherine de Maignelais. =
Why is she known as Sorel when her father was Soreau?

Denis Beauregard...

Sorel is the female form of Soreau, that's all. Actually, the exact
female form would be Sorelle, but at that time, spelling was not yet
fixed.

This usage happened many times in early Quebec records (after 1621).
For example, family names in -et written as -ette (i.e. Frenet and
Frenette, Guenet and Guenette, etc.). Roy written as Reine for a
mother. However, this happened many times but was not very
frequent i.e. you will find very few records where the family name
is written with the female form for a daughter.

This has nothing to do with poetry.

I found four brothers (but no sister) for Agnes : Andre, Charles, Jean =
and Louis. All four seem to have been called Soreau. These four brothers =
seem not to have left a trace. Surely with Agnes in a position of power =
she would have found properties or positions for them?
Her father's brother Geoffroy Soreau became Bishop of Nimes, did she =
have a hand in this?

Apparently she became an orphan quite young. Would it be possible that =
her immediate family was wiped out through disease?
She was first looked after (I understand) by her mother's sister-in-law =
Marie de Jouy, Madame de Maignelais wife of Jean II Seigneur de =
Maignelais.=20

Even the year of her birth is vague, about 1422. Apparently she was =
about 28 when she died.=20

Can anyone help?
With many thanks
Leo van de Pas,
Canberra, Australia