S.D. Codified Laws § 29A-5-404
A conservator of a minor, without the necessity of having to seek prior court authorization, shall apply the income and principal of the estate as needed for the minor's support, care, health and education. A conservator also shall apply the income and principal for the support of any legal dependents who are unable to support themselves and who are in need of support.
In making distributions, a conservator shall consider the size of the estate, the duration of the conservatorship, the minor's accustomed manner of living, other resources known to the conservator to be available, and the recommendations of the guardian or, if no guardian has been appointed, the recommendations of the parent or other individual with legal custody. A conservator shall at all times act in the minor's best interests and shall exercise reasonable care, diligence, and prudence.
SDCL 29A-5-404