Gift card baby shower reasonable amount $ to give

I was invited to a baby shower and since its her second baby she asked for no gifts but gift cards instead. Any time I have ever given a gift card it has been to go along with a theme of actual gifts. So I've always just put $10 on. What would you consider a good amount? I'm not super close but I'm a lot closer to her than most people so while I don't really see her as close she sees me as close? Does that make sense? Her other kid calls me aunty. I just have no idea what amount to put on a gift card.

What amount would you put on?