That i s entirely up to you. Sponsorship is a voluntary, ongoing contribution. Child Sponsorship is generally a long-term commitment, up to 10 years or more. You can sponsor the same child as long as the he or she is studying plus up to such time that the child stands on his/her own feet independently.  

Occasionally there may be a instances where the sponsored child leaves the programme, then if you wish, you can continue the sponsorship with another child.