Can a child fully recover from ocd by the time their an adult?

Possibly: Mental illness is a very dynamic thing. With counseling/cbt (cognitive behavioral therapy) and medicines, we can improve a patients symptoms to the point where they can manage without intervention. The amazing thing about children is the pliability of their brains. A child might not "recover" from ocd, but they should be able to manage it well.

Unlikely : It is very unlikely the child will recover from OCD when they become adults.

Yes and no.: There are no known cures for ocd, which tends to wax and wane over time. However, there are well-established treatments, both medications and behavioral interventions, that can markedly diminish the impairment OCD can cause and help the child continue developing normally in other arenas of life. Cbt has been shown to be especially effective in reducing the likelihood of future episodes.