MIL Vent

I know this might sound ungrateful to some, but I need to get this off my chest. My in-laws are the worse when it comes to my daughter. I can go on and on, but I won't. For Christmas they gifted her some cash (the note said it was for her Stride Rite shoes - shoes we purchased months ago because she needed them, but now MIL is upset because SHE wanted to buy them).  They gifted DH 5x that amount along with a gift.  I don't understand how her ONLY grandchild gets less than her full grown, working children?!  Maybe my family is different. I don't know. In my family, adults don't get gifts. We only give gifts to the children (children meaning still dependent in some sense, so even the colle aged "children" get gifts). Vent over.