Lutecia has a major handicap, namely the fact that she isn't (apparently) allowed to use her primary power-set (much as I'd love to have her get beaten down by some arrogant competitor and then use Hakutenoh to affect an attitude adjustment.
), which might explain why she's eligible.
Another question, though, would be what local tournaments would Nanoha, Fate, and Hayate enter, since all of them resided on a non-administrated world until they were 15.
*suddenly remembers the upper age limit is 19 and has the mental image of
StrikerS Fate and Nanoha entering the tournament*