Is my mother-in-law considered a dependent? Can she transfer her disability and caregiver amounts to me to decrease my tax payable? Please cite with evidence.

Sorry, but this forum deals exclusively with tax issues for the United States.

Your MIL has to file her own taxes; OAS and CPP or any other amount are her responsibility as taxes are due on all. Given that, no she can transfer those to you to reduce your taxes.

H&R Block can assist you with this.