Part 1
1. propitious adj. 有利的,吉祥的,吉利的
Her answer, therefore, was not propitious, at least not to Elizabeth's wishes, for she was impatient to get home.
2. postscript
In her postscript it was added that: ...
3. spare
If Mr.Bingley and his sister pressed them stay longer, she could spare them very well.