Baby Shower Etiquette Question

Thank you all for the advice! She has registered for diapers and wipes, which I have some of from preparing for my baby that never came. I'll give a pack of diapers as well as the blanket ☺️

My brother in law and his girlfriend are having a baby shower next week. I'm not going for emotional reasons, but my husband is. I did however make a gift. It's a handmade blanket. My question is, with a handmade gift, should we also buy something for their registry? Would it be considered impolite to give just the handmade gift?