Hey there Liz,
Welcome to planDisney and thank you for your question! It sounds like you're planning a really fun trip with friends and family to the Happiest Place on Earth - how fun!
According to the Important Details section of the
SoCal Resident ticket page, this offer is valid only for Southern California residents within ZIP codes 90000 to 93599; proof of eligible residency, including valid government-issued photo ID, is required for purchase and admission. Each ticket is assigned to an individual Guest and these rules and regulations apply to each ticket as these promotional tickets are specifically for Guests who live in the ZIP codes outlined above. Therefore, your sister's family would not be eligible for this specific promotion.
However, I would encourage you still to check out the
Special Offers & Discounts page to see if there might be other offers that they would be eligible for!
In the meantime, make sure to check out the
Disney Parks Blog for articles on all the fun things that'll be happening around the Disneyland Resort during your visit.
Thanks again for your question, Liz! I hope you all have a wonderful time on your upcoming trip.
Have a Magical Day,
Greg