Those are the flowers of a Campsis radicans variety, not Wisteria. if your sister had flowers on her Wisteria earlier in the year, that means she has a Campsis growing in with the wisteria - both plants have composite leaf arrangements, so close inspection would reveal differences in the leaves, although their arrangement is similar. If she has never had wisteria flowers, then she hasn't got a wisteria, she's got a Campsis radicans variety. Certainly, the leaves I'm seeing in the second picture ARE those of Campsis, not Wisteria.

The Wisteria leaves are the thin ones top right.