She picked rampion, of course, this being a fairy tale novel, and I go grumble, grumble, grumble because she's not Rapunzel, she's nothing like Rapunzel, putting in one commonality only underscored the fact. There's a certain logic, even grammar, to the fantastic. If you throw together motifs with merry abandon, you end up with a solecism.
Or comedy, I suppose. That may help explain why fairy tale mashup is often comic -- assuming it's competent. But dramatic needs for the motifs to be arranged suitably. Which is of course tricky in itself. You can do a lot of tricks with the motifs if only you can manage to convince the reader that instead of the mother, wishing her son farewell, offering him the choice of a full loaf of bread with her curse or half of it with her blessing, the wizard he worked for offered him a bushel of gold with his curse or a few coins with his blessing.
Fairy tales are the simplest to see it in, but I still remember a retelling of Robin Hood where he was not only the worst archer in the band, but the stories concentrated not on the derring-do but on the discomfort of effectively endlessly camping.
And many an attempt to subvert cliches only reveals that nothing becomes a cliche without being used a lot -- which means, by definition, it must have something going for it. Respect your cliches. There is a reason for their existence.