I didnt read all of the answers but I would just mention it to her in a nice way.
I think we should stop buying my husbands nieces who are married with kids because we buy their kids too and they have 4 little kids between them and one on the way. Its getting to be too much. And I know its better to give than recieve but the nieces have never bought my husband anything. In fact they never even bother except at Christmas so that gets me upset.
But he wants to keep giving because he feels bad stopping, and my husband is my 2nd husband and he has no kids of his own (I have kids/grandkids). So I dont say too much or tell him what to do, even though he has both his parents, sisters, brother in laws, nieces, nephew in laws and great nieces/nephews.
And in the end, the love you take is equal to the love you make~ The Beatles