Re Gifting (The Receiver)?

Do you believe in giving a gift that some else gives you to another person if you don't like it? My sister gave my mother some pj's and my mother did not like them. So she gave them to me for my birthday.I am thankful but when my sister asked me what I got for my birthday I told her.Not knowing that my gift was something she gave my mother as a gift.Should I say something to my mom about this? My sisters feelings were hurt because of this.I love the PJ's but I don't want any ones feelings to b hurt. What should I do?