20 CFR 219.53: Evidence of having a child in care.

(a) Preferred evidence of having a child in care. Preferred evidence of having a child in care is—

(1) If the child is living with the applicant, the claimant's signed statement showing that the child is living with him or her.

(2) If the child is living with someone else—

(i) The claimant's signed statement showing with whom the child is living and why. The claimant must also show when the child last lived with him or her, how long the separation will last, and what care and contributions he or she provides for the child; and

(ii) The signed statement of the person with whom the child is living showing what care the claimant provides and the sources and amounts of support received by the child. If the child is in an institution, an official thereof should sign the statement. A copy of any court order or written agreement showing who has custody of the child should be provided to the Board.

(b) Other evidence. If the preferred evidence described in paragraph (a) of this section cannot be obtained, the Board will require other convincing evidence that the applicant has the child in care.