oh gunting, I like that one as well as the OP's one! I'm 30-something and much closer to 40 than 30, but I think denim dress is a bit 'all age' like skinny jeans, as long as your arse is covered, and being similarly petite, it would be around my knees too.
I think with a cardie, tan boots and brown or navy tights it would look good now, as the weather improves, with Mumsy converse type trainers or with flip flops in the summer.
It might not be long lasting, but at that price, it doesn't need to be a 5 year purchase.