I would graciously thank her and accept the offer...(and keep all the related emails)
perhaps the offer was made in good faith....
maybe it was an offer intended to be used against you at a later date...
your gracious acceptance might affect your mil...
we reap what we sow...
accept it with love and it just may change the motive of the giver
you can not control the thoughts or actions of anyone other than yourself
accept it as a gift of love and it will be a gift of love...