All 7 Uses of

however
in
A Tree Grows in Brooklyn

They made the best of it, however.†
Chpt 8

however = a word used to connect contrasting ideas as when using "though", "in spite of that", "in contrast", "nevertheless", etc.

A few, however, like Katie, continued to watch in the door or hallway when they knew the children were due home from school.†
Chpt 33 *

however = a word used to connect contrasting ideas as when using though, in spite of that, in contrast, nevertheless, etc.

Instead of speaking, however, he closed his eyes for a second and then went into the bedroom.†
Chpt 35

There was an alternative, however.†
Chpt 49

however = a word used to connect contrasting ideas as when using "though", "in spite of that", "in contrast", "nevertheless", etc.

However, she let him buy her a beer, and she sat at the table watching Johnny dancing with Hildy and thinking that in all the world, there was nobody like Johnny.†
Chpt 7

However, it was a fact that not once in all the years of school were Katie's children ever sick.†
Chpt 20

Definitions:

(1) (however as in: However, complications may...)
though (or another expression that connects contrasting ideas)

(Based on idea 1 we might not expect idea 2, but this is a way of saying that even though idea 1 exists, we still have idea 2. Synonyms include in spite of that, despite that, nevertheless, nonetheless, on the other hand, in contrastand but.)
(2) (however as in: However much she tried...)
to whatever degree (regardless of how much; or whatever unspecified amount)
(3) (however as in: However you do it, get it done!)
in whatever way
(4) (meaning too rare to warrant focus)
meaning too rare to warrant focus:

Much more rarely (and arguably incorrectly), however can be used to intensify the word how, as when one says "However did you find her?" Grammarians would suggest using two words for that usage: "How ever did you find her?"