And how is Dorne a proxy ally?
Sansa does not rule the North.
The Iron Islands are ruled by Yara. Also not a poxy ally.

The folks who (if they are allies) would be proxy allies are The Vale and the Riverlands. But we don't know what's happening in either area.

Dorne is almost an autonomous region and they have declared for Dany.
She conquered The Reach. Destroyed it's unified army at the field of fire.

She took the Westerlands or at least the seat of the Westerlands.

She took the Stormlands.