Can the parent-child card see the information of the secondary card?

You can't. The information of the supplementary card of the parent-child card belongs to personal privacy information. The secondary card only has the function of surfing the Internet, but does not have other functions such as voice, SMS and MMS. The main card can't see the information. China Unicom Parent-child Card Package is a product suitable for family use, which can reasonably control and limit children's online time.