The common practice for cryptocoins like Bitcoin is to limit address reuse to preserve anonymity. This is achieved by sending the "change" of a transaction to another address and using a unused address for every transaction. (Research showed that even when best practices are used identities could be derived but that's not the point here).
The Ripple wiki documents something about an Account Familiy which seems comparable with Bitcoins deterministic wallets as decribed in BIP0032. However the Ripple system requires a fee for account-activation.
When using an account family how does one activate such account and how does (I presume)
rippled know that an account from a family is activated?