HORRIBLE

First of all, her voice is very unsupported, sounds hollow and not in tune
She can't finish a phrase because she runs out of breathe
She can't sustain a note because the pitch wobbles
A mess

She was awful as a pop singer, she is even worst as an attempt of operatic singing

The only pop singers ever who could aspire to have had an operatic career are:

Whitney in her prime
Lara Fabian
Monica Naranjo
Barbra Streisand

The end.

The rest can't even support a simple vocal line throughout 2 full measures without drops of volume or hollowness (this comes from an opera singer)