Why did Mary move?

[Gene C]

Anna was also a young woman in need of companionship her own age as well as a social life. She was 22 and of marriageable age. The pickings were much riper in D.C., especially for a lady who had been well-trained in womanly social skills (which she had been at the Martin sisters' school in Bryantown, where Anna excelled at her studies).

Like Weichmann, Rev. Wood, and John Wilkes Booth.

She does eventually marry a nice guy named William Tonry in 1869.
He works for the War Dept. At least he used to, he get's fired five days (?) after the wedding. http://civilwarwomenblog.com/anna-surratt/

Are there any pictures of Anna after 1865?
The blog mentions Anna is buried in an unmarked grave next to her mother. Is that correct? Seems to me that after all she had been through, she deserves a head stone.