There are no other pets or children in the house, this child will be keeping the pet in their room and be responsible for it's care and feeding. The parents will be supervising the care-giving, but the child will be responsible for providing the care or the pet will be re-homed.
Dog & cats are excluded from consideration as they can not reasonably be contained to the child's room. Reptiles are excluded for other reasons.
The space available to be designated "pet space" is 24 inches or 60 cm wide and about 16 inches or 40 cm deep. The pet can be allowed supervised access to the child's room, but not to the rest of the house. The child is expected to be entering college in 5 to 8 years and the status of an existing pet at that point is problematic.
Of pets generally available from rescues or pet stores what should be considered?
Preteen "a boy or girl not yet 13 years old" (but thinks they are old enough to handle responsibility)