Ager or Alexander for surname

[Omajan]

We know that our ancestor was Nancy or Ann Alexander Ager.  She had two marriages here in America.  I have not found the record for first marriage to Andrew Forbes or Forbus in around 1830.  In her second marriage record she is named as Nancy Forbes.    Family information we have shows that she came to America at age 4 around 1814, settled maybe in PA or Maine, came from "Protestant" Ireland.  I have been working on Nancy for 30 years and have just about given up on learning more about her.

My question:  Should I be looking for her surname as ALEXANDER or AGER?  I am convinced that if I could only find the first marriage record, I might know more. 

I am not a novice with genealogy, but am new to Irish genealogy.  I would just like to know if someone can guide me as to which surname I should be working with.  Any suggestions are appreciated.

[Wexflyer]

It would be useful if you could say where you got the names "Alexander Ager" from in the first place.
Also, how do you know she was married to an Andrew Forbes? That information presumably should point to  where  they lived?

[whiteout7]

I would go for Agar as it is a rare English surname in Ireland.

A paysite could help you narrow down the "Ager" families but this could be a spelling error
https://www.johngrenham.com/

I would say her surname is Agar and that perhaps her mother's surname was Alexander.

The first marriage to Andrew Forbes or Forbus in around 1830 in America could be far easier to find than a baptism in Ireland in 1810 ish.

Nancy can be the nickname of Ann or Agnes. She could even be Agnes Ann. 

[whiteout7]

location of marriage of: Andrew FORBES and Nancy Ann ALEXANDER AGER - on 17 March 1831 unknown? -how did they get exact date?

First son William Wallace Forbes born in 1832 in Pensylvania.

"Robert married a second time to Nancy Ann Alexander Ager Forbes (born 1811 in ireland) whose husband Andrew Forbes died in 1835 in Monroe County Missouri"

Marriage to Robert was 1837

NAAA was supposedly a twin - what is the twins name?

Whole lot here:
https://books.google.co.nz/books?id=UJjP_T4h3_AC&pg=PA109&lpg=PA109&dq=nancy+ager+and+andrew+forbes&source=bl&ots=TeGFTb49Ex&sig=41CQ3Rv_xyCEUe4wFNnKKSA9Pao&hl=en&sa=X&ved=0ahUKEwjTl4-wnfPRAhUKabwKHawKA38Q6AEIGDAA#v=onepage&q=nancy%20ager%20and%20andrew%20forbes&f=false

[aghadowey]

From the information posted here (and many posts someone has online at least back to 2000) it's impossible to say what her birth name was. Her father (or mother) could have been Alexander or Ager but she later used the name of a stepfather or relative.

Hannah is also used in Ulster as version of Agnes, Ann, etc.

[Omajan]

I'm not sure how to reply to individual responses. 

1.  The Alexander Ager names came from a relative back in the early 1950's.  A few of Nancy's childrens' death certificates stated Ager as her surname, and I believe one used Alexander.  She died in 1886 in California, no death certificate. 

2.  The information noted by whiteout7 is from my various postings.  I have not yet linked into that posting info.  Have no idea who her twin is/was.  Have not found her on a census with parents as she was married by 1830.  Where the informant got the exact date of the marriage I do not know.  The informant also had birthdates for all the children, even children from the second marriage.  The informant is now deceased, died in the 1950's long before I started genealogy research.

3.  I have searched for the first marriage for 30 years and have not yet found it.  I have found death of first husband Andrew Forbes in Monroe County, MO, have copies of his estate file (he died intestate).  He died 1835, just a few years after their marriage.  Two children from this marriage and I have yet to find what happened to them.  Research has been done in Ralls County, MO and in Linn County MO where she lived with second husband.  She came to California around 1861 or so. 

Thanks to all for your input.  Much appreciated.