House Rules are only synced with Airbnb and Vrbo upgraded connection. For other connected channels, include Vrbo standard connection, house fees should be updated directly on the channel.
By setting your listing as child-friendly, you can attract families who are specifically looking for accommodations suitable for children. You could also consider mentioning child-friendly features or amenities in your listing description.
To set your listing's child policy, follow the steps here to access the listing's booking settings. Under House Rules, activate the toggle for "Suitable for children (2-12 years)" and/or "Suitable for infants (under 2 years)". See more information here.