Final answer:
Walking is a developmental milestone that children achieve at varying ages, typically around the first birthday but sometimes later. Since the 15-month-old in this scenario has normal muscle tone and is showing appropriate responses to stimuli, the nurse's best response is to reassure the parents that "Children often set their own pace" for reaching milestones such as walking.
Step-by-step explanation:
In assessing whether a 15-month-old client's developmental stage is appropriate, it is important to consider the range of ages at which children typically achieve various developmental milestones. Walking is one such milestone. Most toddlers begin walking around their first birthday, but it is still within the normative approach for walking to commence a bit later. Since the child in question crawls, has normal muscle tone, and responds well to stimuli, there is likely no immediate cause for concern.
Motor skill development, including the transition from crawling to walking, occurs at varying rates for different children. There is a broad range of when children hit this milestone, and some may not walk until after they are 15 months old. It is also common for children at this age to pull up to stand and walk with help.
Based on these considerations, the most accurate response by the nurse would be: "Children often set their own pace." This response acknowledges the variations in the rate of development without causing unnecessary alarm to the parents, and it is also the best advice given the normal assessment findings. Referral to a specialist or suggesting a developmental disorder, such as autism, without further evidence is inappropriate at this stage. Similarly, advising to stop carrying the child might not be necessary and is not supported by evidence as a solution to promote walking.