At most I would be tempted to say something vague like, "Hey, I was thinking about making something for the baby. Are there any particular colors you would prefer (or actively dislike)?" Since you already know the colors she's looking at, it really doesn't seem necessary to get any more input than that. And don't feel limited by those colors, just keep them in mind when choosing colors to try to pick something that won't clash horribly with her color palette.