This assessment, similar to the Positive and Negative Affect Schedule (PANAS) for adults, is a valid and reliable tool to assess the frequency of positive and negative emotions in children. While it is often used to assess anxiety and depression in youth, it can also be used to assess the positive emotions that contribute to wellbeing. The PANAS-C consists of 29 self-report questions children can respond to on a 5-point Likert scale according to the frequency they experienced each emotion during the past week. There is a shortened 10-item version of this schedule which is similar in validity and is more efficient to administer.
Ebesutani, C., Regan, J., Smith, A., Reise, S., Higa-McMillan, C., & Chorpita, B. F. (2012). The 10-item positive and negative affect schedule for children, child and parent shortened versions: Application of item response theory for more efficient assessment. Journal of Psychopathology and Behavioral Assessment, 34(2), 191–203. doi: 10.1007/s10862-011-9273-2.
Laurent, J., Catanzaro, S. J., Joiner, T. E., Jr., Rudolph, K. D., Potter, K. I., Lambert, S., Osborne, L., & Gathright, T. (1999). A measure of positive and negative affect for children: Scale development and preliminary validation. Psychological Assessment, 11(3), 326–338. https://edtechbooks.org/-eiJx