[@TheWindel]
She outright stated in an earlier post that they were made of blood and that BS couldn't control them, but far earlier (Arcadia) she said this about them.

[quote]
[@Banana]

If Bonesword wants a bit of her roses, Victoire is very well willing to make a deal with him. He would never be able to control them right without her permission, anyway, since the roses are part of her Primordial Vampire powers. He has the potential, all he needs to is think, "How much is this worth?"
[/quote]

It implies that BS could control the roses, although not well at all.