jellycat NYC diner reservations

i'm going to NYC in early june and i've been wanting to get a reservation but i have a few questions about it.

'm the only one participating in the actual experience, but i'm going with my grandma and mom, how many reservations do i book? do they need reservations too even if they're not participating? how many jellycats can you get per person/reservation? how fast do reservations sell out? i'm kinda nervy about getting them.