Your translation "a share of [her] girlhood" makes me think of Catullus 62.70-72 (the marriage poem):
virginitas non tota tua est, ex parte parentum est,
tertia pars patrest, pars est data tertia matri,
tertia sola tua est
Your translation "a share of [her] girlhood" makes me think of Catullus 62.70-72 (the marriage poem):
virginitas non tota tua est, ex parte parentum est,
tertia pars patrest, pars est data tertia matri,
tertia sola tua est