Heh, there is absolutely no reason to be a jerk to the mother. In all honesty a pragmatic magus would want to work with the mother for training purposes. If its not blood, but a Hedge Tradition that leads to the Gift, taking the daughter would destroy the line.
Possible scenarios:
- A hard line traditionalist who would oppose at all cost the Tribunal's decision, and wants to break the Mage-Noble line this way and doesn't care what a lowly hedge tradition can offer.
- An opportunist who wants to discover the secret and is paid by Jerbitons / Merceres.
- A bribed young mage, who is absolutely not fit to train a mage yet. Upon the Tribunal's is uproar a friendly Bonisagus (who has originally paid the young mage/scapegoat) takes the apprentice by the right of Bonisagus, moves to live with the family and will try to integrate the hedge tradition's secret by working together with the family as their best friend.
The hedge tradition's secret is a very limited fertility magic: Only a fertile gifted female mage can use it. During the whole pregnancy period specific charms are constantly held close to the mother. Signs /runes are painted on the mother by herself. Counts as full time laboratory work for the 3 seasons and the pregnancy has to start at a season's beginning. Using any other supernatural ability (eg.: spell casting) during these three seasons interferes with the process and decreases the Fertility lab total by the used ability's level or the spell's magnitude.
Odd thought- in many myths and traditions mystical power is granted to the ruler of the land- what if the Gift comes from her title?
In a related issue- if a magus has a child they have offered to teach to prepare for apprenticeship, then plans to auction or sell off the (highly trained) child as an apprentice, assuming they start at the age of 5, what happens when someone else kidnaps and opens the child as an apprentice- can the person who trained the child demand some form of payment for their time and effort as deprivation of magical power (assuming payment would be made in vis)
The needle that has to be threaded is that an apprentice isn't an apprentice until the Arts are opened. Anything that happens to the child before the Arts are opened is fair game, with respect to Lex Hermetica. If the Arts are opened, then the master has the responsibility to teach the apprentice one season out of every year. Normal apprenticeships are 15 years, begun once the Arts are opened, but a clever master could teach things and set a gauntlet on something unrelated to what has been taught increasing the chance of failure and also keeping the apprentice longer.