Final answer:
The nurse should anticipate the gross motor skill of creeping up stairs in a 15-month-old toddler during a health maintenance visit, as this is a common developmental milestone at that age.
Step-by-step explanation:
When assessing a 15-month-old toddler, a nurse should anticipate seeing the gross motor skill of creeping up stairs. At this age, toddlers are still perfecting their walking skills and may not be able to take stairs in the adult pattern of one foot per step. Instead, they often creep or crawl up the stairs, which is a milestone they work towards before mastering the ability to walk up the steps more steadily.
Some other developmental milestones for toddlers around this age include standing up unaided, walking with or without support, and beginning to use objects with more precision, which could include banging blocks together or turning the pages of a book. While they might be starting to handle cups and may attempt to scribble, drinking from a cup without frequent spills and scribbling spontaneously are skills more consistently seen slightly later in development.