When your child receives their vocation, it usually is not an event, but an evolving process which you have likely witnessed unfold over time that culminates in a concrete decision to follow the vocational call from God.
Your diocese should have a priest or sister appointed to assist individuals start, or further their vocational discernment. This is a good place to start for local support to nurture this new calling.
For your child this will result in either unknown exploration or a defined direction. If this realization crystalizes for the consecrated life, priesthood, or brotherhood it may or may not feel attached to a specific community or way of life, i.e., Franciscan, Dominican, Benedictine, or diocesan. At this point it is important to avail your child the opportunity for discernment retreats, or events that will allow your child exposure to many communities to assist in defining their call. If your child has already felt a call to a particular way of life, then starting with those communities is a good place to begin.