An Aged Aunt Remembers, or Putting Two and Two Together

My great-aunt Brendice Gerner Davis was in her 90s when I asked her about her father, Fred Gerner, his siblings and parents, and her own siblings.  Her memories were short on her grandparents:  she couldn't remember Fred's parents names at all.  But she gave me some information:

About Fred:
Place of birth:  Anaheim, Germany
Immigrated:  when 6 months old
Siblings:
- a girl Emma who married Alf Heusel
- a boy Charlie

Some time earlier (years, possibly decades) one of her daughters-in-law made notes as Aunt Brendice either answered questions or told stories.  I received a scan of the notes from Brendice's grandson.  Some of the information differs from the information she sent me.

About Fred:
Born in:  Mannheim, Germany
Siblings:
- Christian
- John
- Charlie
- Emma

What of this information should I have recognized earlier as correct?  Should I have assumed it was all correct?  I've searched for Alf and Emma Heusel with no success.  Absolutely none.  Correct or incorrect information?  I've searched for Gerners coming from Germany without any positive success, though there are some possibilities.  Correct or incorrect information?  (Even if I found immigration information I wouldn't assume it was the family when I know so little.  I think it's better to stay closer to home and gather as much as information as possible before jumping to another country with limited information.)

When I found Christian Garner and Christopher Gardner in the 1860, 1870, and 1880 U.S. Census records whose children had similar names I began to wonder how much of the information Aunt Brendice remembered could be accurate.  Perhaps more than I thought.

So I've begun the search for Fred Gerner's siblings as named above.  I've already found "Charlie" who became Charles.  I have leads on the others.  My hope is that death records will name Christian and Elizabeth/Mary E. Sthal (or variation) as the parents in marriage and/or death records and in obituaries.  Without a will or probate information for the older Christian Gerner, census records and marriage and death records are my obvious options for Fred's siblings.

I have always read that searching the collateral is sometimes helpful, sometimes essential.  I believe that in this circumstance, if I'm to make any progress, it's my only option.

--Nancy.
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