As a Play Kits subscriber, you can apply the gift to your existing subscription to extend it, or you can activate the gift for a different child.
If you choose to apply your gift to an existing Pay per Kit subscription, the gift will apply to the Kits that are scheduled to ship next.
If you add the gift to a Prepay & Save subscription, the gift will apply to the Kits that are shipped immediately following the delivery of your final prepaid Kit.
For both cases, your Play Kits Subscription will continue following the delivery of the gifted Play Kits, as long as you're an active subscriber.