Obligation for Appreciation

Last visit of my LOs great aunt brought some second hand clothes for LO saying it was from my SIL. I thanked the aunt for it. However, SIL hasn't given any presents to my child before except her 1st birthday. She never responded my warm congrats message after her son was born, nor does she make an effort to be in our lives. Knowing this I don't want anything from her. In fact I put the clothes away. My MIL tells me today if the clothes fit because my SIL hasn't heard from me. Really, what does she want a gold medal. Normally, if it was someone I had a decent relationship with, I'd send them a thank you message. But I don't want to give this one the satisfaction, besides my husband told my MIL that the aunt brought it and we said thank you, and he shrugged it off. I don't want her left overs. I prefer for her to ask me herself if I need anything instead of this way and expecting me to reach out. Am I right or am I wrong?