Can Lighthouse help me control the amount of screen time my child spends online?

Yes, to a certain degree Lighthouse will be able to assist with this. In the Parent app, you will be able to switch the Internet off/on immediately or choose to schedule between which days/times your children can access the Internet on their device.

Some of the latest smartphones do offer screen time monitoring. Read more here (for iOS) and here (for Android) to find out how to activate it on your device.