I found your Mary Follick, as head of house in the 1840 and 1850 census for Wayne, Montgomery Co. Indiana.
Isaac appears in the 1830 census for Colerain, Hamilton Co. OH as does Lydia (a few households away)
In 1850 Mary is 51, b. Eng, and she has 3 sons with her - Joseph J 19 b OH, Oliver P 17 b OH and Isaac P 14 b OH
If we look at 1840 census (no names, just ages) the 3 boys above are represented but there are also 1 male 10-16, 1 male 16-20 and 1 female 10-16. I assume your ancestor is the male 16-20 but that still leaves 2 more children, a son 10-16 and a daughter 10-16.
Then we look at 1830 and here Isaac is aged 20-30 with 2 sons, 1 under 5, 1 5-10, his wife age 20-30 and 2 daughters 1 is under 5, 1 is 10-15. We know Mary should be about 31 so she fits in that 20-30 age category. Your ancestor would be about 7 so he fits in the 5-10. The 10-16 year old male in 1840 could be the under 5 in 1830. The female 10-16 in 1840 could be the female under 5 so we have one more daughter age 10-15. That makes 3 unaccounted children
Phew, I've almost lost count! If I'm counting accurately that gives Isaac and Mary these children:
Dau b 1815-20 Son b 1820-25 (your ancestor?) Son b 1825-30 Dau b 1825-30 son b 1835-40 (Isaac P?) son b 1830-35 (Joseph J?) son b 1830-35 (Oliver P?)
We know the family was in Ohio in 1830 with Isaac, all the way up to when Isaac P was born (circa 1836) but were in Indiana without Isaac by 1840, so that narrows their migration to 1836-1840 or so.
Hope this helps, I haven't found anything else but if I do I'll post it here
Btw you might want to join my Rootsweb FOLLICK mailing list. See http://olivetreegenealogy.com/http://olivetreegenealogy.com/ and click on MAILING LISTS