Note 1: (a-la-mortal) This probably means that her emotions were intense. American Heritage Dictionary gives this as one of the definitions of "mortal": Of great intensity or severity.
Note 2: (the Lady of Branxholm Hall) This quotation belongs to one of Sir Walter Scott's poems, The Lay Of The Last Minstrel. Excerpts from the poem are available on line, curtesy of the University of Toronto, Canada and their "English Language and Literature" web site.
The reference Miss Austen used was from the First Canto, Section XX. Here, the surrounding sections are also given:
The Lady sought the lofty hall,
Where many a bold retainer lay,
And with jocund din among them all,
Her son pursued his infant play.
A fancied moss-trooper, the boy
The truncheon of a spear bestrode,
And round the hall right merrily
In mimic foray rode.
Even bearded knights, in arms grown old,
Share in his frolic gambols bore,
Albeit their hearts of rugged mould
Were stubborn as the steel they wore.
For the gray warriors prophesied
How the brave boy, in future war,
Should tame the Unicorn's pride,
Exalt the Crescent and the Star.
The Ladye forgot her purpose high
One moment and no more;
One moment gazed with a mother's eye,
As she paused at the arched door:
Then from amid the armed train,
She called to her William of Deloraine.
A stark moss-trooping Scott was he
As e'er couch'd Border lance by knee:
Through Solway sands, through Tarras moss,
Blindfold he knew the paths to cross;
By wily turns, by desperate bounds,
Had baffled Percy's best blood-hounds;
In Eske or Liddel, fords were none,
But he would ride them, one by one;
Alike to him was time or tide,
December's snow or July's pride;
Alike to him was tide or time,
Moonless midnight or matin prime:
Steady of heart and stout of hand
As ever drove prey from Cumberland;
Five times outlawed had he been
By England's King and Scotland's Queen.