If she needs a better instrument you're best off going and trying some out and seeing what she likes. How old is she, what standard is she and where are you based? What size will she require? Budget? If she's a decent standard you can't really just buy an instrument for her. Shops like Paul Ayres in Manchester, Hamilton Caswell in Bristol, H George in Blackpool, and Ealing Strings in London will sell upgraded student instruments that might be good enough. If you on the other hand have a daughter who's looking at university/conservatoire, you need to carefully consider what you purchase. Happy to talk via pm. I'm a violinist/violin teacher, and do much work for the local music hub for context.