With most control systems a cheap pad/phone used as a dedicated controller can support the babysitter. There is no need for services, such as email, messaging, or cell service. The babysitter will have the services on their own phone. You might want to tinker with some subnets in order to allay security concerns.

Use of a phone/pad is probably not part of AVA’s business model.

On the AVA images I see some buttons along the body’s edge. Are these used for Volume/Mute?