I have two under 18. We did not consult them when we chose guardians, mainly because i didn't want it to be a popularity contest. We made the choices we made for specific reasons, some of which my kids are not entirely privy to. We also agreed to reevaluate our choices every 5 years or more often as circunmstances change.
My DS19 will not have a guardian, nor do i expect him to care for his sibs. He is not a caregiver by nature, although he is a very nice kid. He has his own growing up to do.
My 12yo was disappointed when i told her who her guardian would be, should we die, but then she got over it. She's a roll-with-the-flow kinda kid. Her guardians are in a stable marriage and manage thier own money well.Their religious beliefs are similar to ours. They are both college educated and will see that she stays in contact with both sides of the family, and especially her older brother whom she is so close to.
My 10yo is severely mentally handicapped and we chose a different guardian for him. We felt it would be too much for one person to take them both. He will also go to a family with no other children. Both guardians are college-educated and manage their money well. This guardian will probably also be responsible for placing him in a group home eventually. Ultimately, my DD12 will be DS10s guardian, after she turns 25.
Our attorney put it this way: "Who would be better that foster care if you died yesterday?" Yike! That put it into perspective. There will never be parents as good as you, so forget finding the "perfect" guardian. They don't exist.