For a luxurious type of present you could go for a spa day, or beauty make over there's
beauty vouchers on groupon that are around £20 for local salons - obviously more for designer type salons. It could be a wedding pressie, or just for something for her to look forward to once the wedding excitement has all died down.
I was BM for my sister and got her a hair and make up day and she ended up using it as her wedding make up & hair lol!