100% agree with all of this. Sister is the only AH.

And OP, it sounds like your sister may have done a bit of damage to some of your family relationships. If you haven’t responded to the angry texts already, I’d suggest something along the following lines:

“Hi X. I’m not sure what Sister told you, but I want you to know that I am very grateful for the gift you got me. I was upset after the party because most of the gifts were for the baby and since most of my life has revolved around the baby lately, I felt a bit forgotten about. I know none of that was intentional and again, I really like the gift. [Describe a specific feature of the gift that you like].

If you still want the gift back, I will return it. To be honest, I’d be quite hurt if I heard someone was upset over a gift if gotten them, so I understand if this is the case. Either way, I truly hope there are no hard feelings - even though I was sad, I was also grateful and I certainly never wanted to offend anyone. I thought it would be safe to share my feelings with my sister and I was mistaken. I’m sorry for that.”