Won’t take a bottle

My daughter is 7 weeks old and is ebf and completely refuses a bottle. I’m going to a wedding on Saturday and my parents are watching her. I’m terrified that she won’t take a bottle for them and isn’t going to eat. And tips to get her comfortable with taking one? I’ve been trying almost everyday to give her at least one bottle and she always refuses so i end up giving in and nursing her, which i know isn’t good to do but if i don’t then she won’t eat :(