Hi there Javier!
Thanks for bringing your question to the Disney Parks Moms Panel. Your family is going to have double the fun at the Disneyland Resort with your twin girls! You will be happy to hear that whether you
purchase a Park Hopper Ticket or a One Park Per Day Ticket, you are allowed to come and go from the parks throughout the day as you please. With the ticket you are describing you can definitely leave for that midday nap or even to do some shopping in the
Downtown Disney District and return back to the same park later on.
Since you will be arriving in May, you don't want to miss the limited-time
Pixar Fest that starts April 13, 2018. This is a celebration of your favorite Pixar films and Characters with events at both Disneyland Park and Disney California Adventure Park. Your little ones will love the dazzling fireworks display, Together Forever - A Pixar Nighttime Spectacular, or the breathtaking Paint the Night Parade. They can even see many of their Pixar pals in the Pixar Play Parade and at new Character Experiences! Keep an eye out on the
Disney Parks Blog for announcements closer to the dates of your trip for more information.
If you have any other questions, feel free to stop by again. Have a magical day!
-Jennifer