Hi Guadalupe, welcome to planDisney, I'm happy to help!
So kind of you to be purchasing tickets for your sister and her children! As you mentioned proof of residency, I think you're considering the
Southern California Resident Weekday Ticket Offer. Please know that this offer is only eligible for Southern California residents within ZIP codes 90000-93599, and proof of eligible residency is required for purchase and admission, which can be in the form of a valid government-issued photo ID. As your sister and her children reside in Oregon, they would not be eligible to use these tickets. But don't fret! You can still purchase
Standard Theme Park Tickets for them, and these do NOT require any proof of residency. These tickets are for ALL Guests! When purchasing standard theme park tickets, you'll have the choice between the one park per day tickets and the park hopper tickets. I personally prefer the park hopper tickets as they allow you to "hop" between the parks, giving you flexibility and more control over your schedule.
Also, when purchasing tickets, you'll be given the option to add on the
Disney Genie+ service for an additional fee. Genie+ gives access to the
Lightning Lane entrances throughout
Disneyland Park and
Disney California Adventure Park. The Lightning Lane entrances hopefully give quicker entry to certain attractions versus waiting in the standard standby line. As your sister has kiddos, Genie+ could be worth looking into! But she doesn't have to make a decision right away. She can always add the Genie+ service onto her tickets when she's inside the parks!
If you have any more questions, don't hesitate to come back!
See ya real soon!
Jin