Including an infant in ADR head count?

[Travel Guru]

Hi all! :wave:It looks like my DB and DSiL will also be at WDW during our trip next June, and while we're planning our trips separately (they are trying to rent DVC points through the company that manages their timeshare on Cape Cod), we are planning to have at least one meal (probably TS) together each day that our trips overlap. My DNephew will be almost 1 1/2 on the trip - when I book ADRs that include DB and his family, do I include DNephew in the head count? Does he count toward our party's size for "mandatory" gratuities (i.e., parties of 6 or more), since he would be the sixth person in our party? We've never traveled to WDW with a baby in the party before, so this is a new wrinkle for me!TIA,- Laurie :)