[speleding]

This has been covered on HN before, the solution is pretty simple: just use a (free) Google Apps account instead and create accounts for your children. You will be responsible for complying with COPPA yourself instead of Google.

All you need is a domain name, but it's a good idea to have that anyways in case you ever want to leave. I use this solution with my kids and it works great because it also allows me to control access to certain services and reset passwords for them, etc.