In Re Scheller, 325 S.W.3d 640

Amanda Scheller died in Sep. 2007; Scheller is parent of two young daughters now living with him in Austin.
Pemberton and Judy Pemberton previously visited Scheller’s daughters in Crockett, TX roughly every 4–6 weeks.
In 2009, Pemberton filed suit for grandparent access under Tex. Fam. Code §153.432 and sought a court-appointed expert to assess potential harm from denial of access.
Trial court issued temporary orders granting Pemberton limited access and appointed a single expert to act as guardian ad litem and to evaluate potential harm.
Scheller sought mandamus; the court of appeals stayed then lifted the stay; this Court grant mandamus to vacate the temporary grandparent-access order, while upholding the expert appointment as guardian ad litem.
Court holds Pemberton failed the hefty burden to show denial would significantly impair the children’s health or well-being; appointing an expert did not infringe Scheller’s parental rights.

Issue	Plaintiff's Argument	Defendant's Argument	Held
Whether the trial court abused its discretion grants temporary grandparent access	Scheller; Pemberton failed to overcome presumption that denial would significantly impair health/well-being.	Pemberton; evidence showed potential emotional/physical impact on grandchildren from lack of access.	Yes; trial court abused discretion; must lift temporary access order.
Whether appointment of an expert guardian ad litem/psychologist violates parental rights	Appointment infringes fundamental parental liberty.	Appointment is permitted to determine best interests and does not infringe rights.	No; appointment permissible and aligned with best-interests determination.
Whether mandamus relief is appropriate to remedy the abuse of discretion	Court should deny Pemberton’s petition and preserve parental autonomy.	Relief warranted due to irremediable error in temporary order.	Yes; mandamus relief granted conditioned on vacating temporary order.

In re Derzapf, 219 S.W.3d 327 (Tex. 2007) (parental rights presumed and state should not intrude without substantial showing of harm)
Mays-Hooper v. Mays-Hooper, 189 S.W.3d 777 (Tex. 2006) (parents have primary control absent substantial showing of harm)
Troxel v. Granville, 530 U.S. 57 (U.S. 2000) (parents have fundamental liberty to make decisions; state intrusion requires justification)
In re Chambless, 257 S.W.3d 698 (Tex. 2008) (parents enjoy fundamental right to care, custody, and control of children)
In re Custody of Smith, 137 Wash.2d 1, 969 P.2d 21 (Wash. 1998) (state cannot substitute parental choices with third parties absent compelling interests)