I think your Whelehan family came from the townland of Derrymore in Killucan civil parish. I located an 1881 civil marriage record on the free site www.irishgenealogy.ie for a Teresa Whelehan from Derrymore. See the second record on this link. NOTE father's name was shown as John.
I also located an 1876 marriage for an Elizabeth Whelehan who was from Derrymore with father John. Elizabeth was also from Derrymore. See third record at this link
I will do more research looking for death records.