I’m trying to think where this will happen though? Thunder possibly but I’ve seen three small people fit in a row. Spaceship Earth, probably not. Figment, probably not. My guess is Mine Train, Slinky Rockin, and Everest are likely. I can’t think of any other rides where there is this possibility. One thing you have to watch for on Slinky is that there are no single riders, but they may put one person from a party of three with another old numbered person to fill both seats. Had that happen.
Heres my story. I’m a grown man with a daughter and son who single rode Space Mountain at
Disneyland (2 side by side seats) Because no one else wanted to ride. When I was called to board, I was put with a girl my daughters age (7-8 at the time). Her parents were riding together behind us. I thought it was strange and even asked if they wanted to sit with her and I’ll sit with one of them. They said no, that she wanted to ride without them. Okay, whatever. That girl chatted me up like nothing else. She was so excited to ride. She told me how she was going to go no hands and scream and all that. I told her that my daughter was scared to go on and how brave she was. She told me that I need to convince my daughter to go on. All this while waiting to get on next and boarding. We rode together, screamed, had a great time. The point of this is that kids will find a way to have fun, and if they want to be there, they may not mind a complete stranger who will genuinly want to be their ride buddy for the next several minutes. I understand your situation because I too have an 8 and 10 year old. Do what you feel is comfortable. However, us single riders aren’t so bad.