Hmmm, in terms of guardianship people's situations change alot over time. Someone who would be very capable and willing to look after Lex this year might not be able to down the track.

But having an adult person around who is willing to support a child, yet isn't parent-y is very good and it sounds like your extended family will be wonderful for them. I had to find my own older person to talk to growing up and I think if a child needs to and has access to lots of different people they will find the one they are the most comfortable with (one of my childless aunts turned out to be fairly cool and she wasn't my godparent either).