I wouldn't place to much emphasis on the discrepancy with the ages. This was very common. The 1880 census is probably the most accurate census in terms of age for James Cole for example. It's easy to remember 6 mons, not so easy to remember exact ages 20 yrs later, especially when this was not a focus of theirs. My great-grandmother was listed as 1yr in the 1880 census and in 1900 she was 16. You do the math. In this case, I found the 1880 census to be a more accurate age for her (easy to remember).

Good Luck in the rest of your search.