。
She'll probably help me choose a new car.
Literal
She [topic-は] new-car [object-を] choosing [for-のに] help [object-を] will-do-for-me [probably-でしょう].
The のに here is not the concessive 'despite' but the purpose marker — 'for the purpose of choosing.' 手助けをする means 'to give help, to lend a hand,' and ~てくれるでしょう combines the benefactive ('will do for me') with the probability marker でしょう ('probably, I expect'). The sentence expresses a hopeful expectation about receiving help.