Donation/Favors Help!

I am a little torn. My fiance and I are not a big fan of wedding favors and would prefer to make a donation to a charity that is close to our hearts. We have both lost grandparents to strokes and would like to put the favor money towards that cause. However, my mother really wants us to give our guests something. As they are covering a majority of the wedding expenses I want to please her too. I am thinking of making chocolates and putting them in plastic bags as a small favor that will not take away much from the donation. According to what I have read on this board I should give them the chocolates as a favor with no mention of the donation. Then maybe mention the donation at the memory table by pictures of our grandparents but not connect it to the favors? Sorry this is long.