When it comes to children and the Internet there are several things that should be considered. First, many devices offer options for parental control to select certain content and avoid other. You can check for these controls in the settings menu of a device or where you can setup the basic preferences of a service.
Be aware of this option and other privacy implications when buying a device or using a certain service and consider them before making a decision. Make sure you understand how the device or service works.
Furthermore, it is useful to discuss the use of equipment with your children and observe how they use it. Make sure you and your children are confident with the use of a device or service because you understand the implications. For example, do you understand what happens to the data that a connected toy gathers while in use by your child? Where is recorded voice data being stored? Does the device depend on cloud services? How is the data being analysed and used by the company that sells the device?
Secondly, any choice that you make for your child and any piece of personal data you share will most likely have more implications for your child than for you. For example: is it a good idea to post a picture of your young kid on your social network profile? Potentially, this picture could be used to profile you and your young child in order to be aware of your interests, needs, etc. While this is a conscious choice you can make or not, your child does neither have the knowledge nor the maturity to take such a decision. Nevertheless, the personal data you gave away about your child will be on the Internet for a long time, if not forever and can be easily found by many people.
It is important that children grow up with Technology and that they are confident in using it. But consider the consequences of your choices and search for information or ask vendors if you are unsure how a device or a service works and how it impacts the privacy of your family.