Hey!
it seems it is normal, as on the CIC website it says :
Parents and grandparents
31-55 months
Working on applications received on September 11, 2007-November 17, 2009*
Issuing acknowledgement letters for applications received on April 29, 2011
So you probably will get a letter in 4 months to say they have received your application, but it will take time.
Good luck,
Sweden
