N.M. Stat. § 32A-1-10
Petition; who may sign.
A. A petition initiating proceedings pursuant to the provisions of Chapter 32 [32A],
Article 2, 3B, 4 or 6 NMSA 1978 shall be signed by the children's court attorney.
B. An affidavit for an ex-parte custody order may be signed by any person who has
knowledge of the facts alleged or is informed of them and believes that they are true.