Either say no or charge them ๐คท๐ปโโ๏ธ. sometimes, these people are not worth our time even though it's family.
I did this twice with my in-laws and the extended family, and it's never a few pics, plus them asking if I can make them look slim or small and edit this and that. Like, I'm not a magician! ๐ ugh! I can tell you more about it, but I changed, and I charge them if they want my service, no exemptions.
$400 for a wedding? even if it's your first one I think it's low balling yourself. just be thankful she ghosted you cause you don't want to do all that work for that price.