Hi, Gaby!
Welcome to the Disney Parks Moms Panel, and thanks for your Disneyland Park questions.
I'm a firm believer that a stroller is a must with young children at the Disneyland Resort, and if you have two children who won’t be able to keep up with walking for extended periods as you explore the parks, it’s smart to bring one with two seats. While I’ve not visited the parks with a double jogging stroller myself, I’ve traveled with friends who did. Although it can be a bit trickier to navigate or fold, you’ll be able to carry it onto the Disneyland Railroad with no problems, especially if you look for the seats toward the center of the cars with no bench in front of them so you have more spare room to hold your folded stroller.
Pirate's Lair on Tom Sawyer Island is not accessible to strollers since Guests must navigate dirt trails, bridges, steep inclines and narrow passages in some areas. You will need to leave it in a stroller parking area and walk on the attraction with your kids.
I hope this helps, Gaby! Have a pixie-dusted vacation and write back to me with any other questions you may have as your planning continues.
Wishing you magic,
Courtney