I’ve seen people use a gift from a parent for proof of funds, but I’d be careful about assuming that a notarised gift deed alone is enough. The deed establishes that the money was given to you and is irrevocable, but IRCC can still look at the overall financial history and supporting documents.
If the amount was transferred recently, I would keep the bank trail showing the transfer from your mother to you, along with the gift deed and your bank statements. If possible, having reasonable evidence showing where your mother obtained the funds could also help explain the source if an officer asks about it.
I’d rather provide a clear paper trail upfront than rely only on the wording in the gift deed.