That's very interesting! Do you think that this also applies to
Nell as a pet form of
Eleanor? So that would mean
Nelly was rhymed with
Elly?
On the other hand,
Nell is more common as a pet form of
Helen. "Hell" was obviously a bad abbreviation of the name. Since
Helen (and
Eleanor too) has n in the middle, do you think that might have influenced the addition of n at the beginning?