My stepdaughter left her 2 children aged 2 and 3 with my husband and I so she could move out of state and "get her life in order". They have been without their mother since the beginning of July. She has called 5 times but has never asked to talk to her children. Is this considered abandonment in the state of Utah??

Not anything criminal, since she left them in care and custody of you, and they are well cared for.

For custody or guardianship this can be used to in filing motions in court