The additional background is sad, not least because your DSD lost her mother young, but because your DH is treating that loss as a permanent infirmity of hers that could be assuaged with monetary items, or trying to make every other aspect of her life better than that of her peers as though that could compensate.
He is not doing her any favors by this treatment, aside from the rifts he is sowing between other family members, yourself and DS included, but not exclusively.