Mama of a baby girl here
I've made her several quilts as well as a few for friends, so I know what you mean. There are a lot of modern prints that are super popular right now, but personally I love old-fashioned baby quilts. My favorites are ones made with 30's repro/feedsack fabrics, try looking for those. I buy a lot of fabric online on Etsy and usually find good deals on FQ bundles there. As others have mentioned, ask the mother what colors she is considering for the nursery and go from there. If I had to make a new baby girl quilt now, I would love to use California Girl by Moda - sweet and old-fashioned but a little modern with the grays and yellows -
https://www.threadbias.com/fabrics/f...-38-fabrics--5
Here are a couple I've made for my daughter: