I have a feeling that no matter what, it will be wrong....get them a cd and its the wrong artist, get them a book and they don't let them read that series, get them a doll and they are too old/wrong kind of doll.
I had a similar situation, with my own brother and SIL. I got my two nieces (13 and 10 at the time) nail polish kits, oodles of different colors, stickers, jewels, glitter, manicure set, dryer, top coat, you name it. nothing was said at the time, but when they were on their way to take the girls back to their mother, 10 yo niece decided to paint her nails....in the car....during a 5 hour trip. of course one of the colors spilled in the floorboard. I heard about it all year because of course it is my fault (I wasn't in the car. I had no control over where the nailpolish was even packed). Brother and SIL tell my mother that because I ruined their car, they decided to get the most obnoxious noisiest toy for my child. (I really didn't care because I am the mom that goes down the toy aisle trying out all of the noisy toys
It wasn't me, it was what they were dealing with. They didn't want to take the kids home because too long of a trip. they didn't like the girls mother. other things that are too cumbersome to tell here. it's their own issues.