Turbo tax has me filing as 'single' though I was unmarried and paid for more than half living expenses and supported qualified person.

Single is right unless you qualify for Head of Household based on your son.  Has she lived with you the Whole Year?  She had to make less than $4,050 total income to claim her.

Oh when was your son born?  He should give you Head of Household Credit.  A child born (even on Dec 31) is considered to live with you the whole year.  So pick the Whole Year at the top of the drop down box.

That did it. I had him as "2 months", not the whole year. Thank you! Thank you! Thank you!

Glad I could help.