Eid gift given as charity: was it the right choice?

Assalamu alaikum warahmatullahi wabarakatuh. Today a brother gifted me about $50 for Eid, may Allah reward him abundantly. Honestly, I wasn't totally sure why he gave it to me-neither he nor my parents explained-he just said it was for me. When he noticed me heading toward the donation box, he actually told me not to put it there. But after thinking it over, since the money was now mine, I went ahead and donated it anyway. It felt a bit odd keeping it, and giving sadaqah seemed like a good deed. Later, my parents asked what I'd done with the money, and I told them I'd given it to charity. They got upset, which I understand-we're pretty tight on money, alhamdulillah we manage for food and basics, but we're not well-off. They explained that the brother knows our situation (I'm in college and still live at home) and gave the gift to help out. They said if I didn't want it for myself, I could've given it to my older sister, who really needs an eye check-up and glasses. Now I'm feeling torn. On one side, we didn't need that money for immediate essentials like food or water, so giving sadaqah felt okay. But we don't have a steady income, and the money could've helped with things like gas or medical needs. I also recently came across a hadith where the Prophet (peace be upon him) mentioned that charity to a family member brings double reward. Would it have been better to give it to my sister? Jazakum Allahu khayran for any thoughts.