Please read carefully.
CIC says:
Who can be sponsored (by your uncle and aunt)
They can sponsor:
* parents
* grandparents
* brothers or sisters, nephews or nieces, granddaughters or grandsons who are orphaned, under 18 years of age and not married or in a common-law relationship
* another relative of any age or relationship but only under specific conditions (see Note below)
* accompanying relatives of the above (for example, spouse, partner and dependent children).
Note: they can sponsor one relative regardless of age or relationship only if they do not have a living spouse or common-law partner, conjugal partner, a son or daughter, parent, grandparent, sibling, uncle, aunt, nephew or niece who could be sponsored as a member of the family class, and they do not have any relative who is a Canadian citizen or a permanent resident or registered as an Indian under the Indian Act.
for more details:
http://www.canadavisa.com/canada-immigration-discussion-board/index.php?action=post;topic=84026.0;num_replies=0
