History of Feminism

...your SIL is insecure and may have been worried/embarrassed about having the toy opened in front of the family. I assume her husband/your brother was at this gathering. Has he said anything or have you talked to him at all about it? IMHO a spouse will often side with their mate out of devotion but it will be the more outspoken of the couple to bring up issues. If your brother is the source of the issue, you should speak to him about it. The conventional wisdom is 'to learn, go to the source'.

In any case, now that the gathering is finished, the source of the possible embarrassment is gone so this all may no longer be a big deal. If I am right, the core of the problem is the pink/girly packaging, which is marketing's way of attracting the attention of parents with daughters. A little boy in a toy store won't be put off by a package with a girl pictured, he'll see the toy first and the girl second. It takes a few years for children to learn the pink and blue prejudice from his elders and the odd thing of it is that in the early 20th century, it wasn't that uncommon for a baby boy to be dressed in pink gown.

Are you over-reacting? No. It is a sad thing to have a gift given out of love rejected even if it's not handed back publicly. He should be encouraged in his culinary interest as he may be the next great chef. When I got married over 30 years ago, the extent of my cooking was a grilled cheese sandwich. Almost all of my cooking lessons were from my wife. My mom was okay with me knitting and doing some minor sewing but never encouraged me to cook much. My wife, who has eaten my mother's cooking, thinks perhaps that's a good thing.