I am sure about Julia Ann Dunn. I believe she was probably named for her grandmother Julia Ann McGrew Dunn who I also have as being buried in Logan Co. On the 1870 census from Logan Co., Julia is 10 years old with parents Andrew and Sarah. No other Julia shown so I believe that grandma Julia died around the time little Julia was born.

This is what I have for the children of Andrew and Sarah Dunn.
Olaphe b. 1854
Frank b. 1856
Isabell b. 1858
Julia A b. 1860 d. March 7, 1889
Emma b. 1862
Grant b. 1864
Andrew b. 1866
Henry b. 1866 if this date is correct, a twin to Andrew.
Leroy b. 1873
Charles b. 1879
I don't have a Sarah so I've probably missed her somewhere.
If you have some corrections please let me know.