Board Thread:Questions and Answers/@comment-19203513-20130914101051/@comment-3335844-20130914105756

It would only level upto around level 15, so you still need to feed at least 5 more of her maga.

The way skill level rises is that every 5 level the daemon gains a level, it's skill level increases by one. So if I assume you leveled your Sensu WITHOUT the maga, at level 30, it should only be at skill level of 7. Therefore you absolutely need 13 of her maga to max her skill.