"Komu pomagłaby?" is not correct?
You could say "Pomogłaby? Komu?" which puts more stress on the fact that we don't believe she'd help anyone.
Not exactly natural sentence to say...
My response, "komu ona by pomagała", should be accepted.
Is this acceptable? Who would she be helping?
I think the Polish answer can be added as an interpretation of English "would help", but I don't know if "would be helping" can be accepted if Polish had "by pomogła".
what about : Komu ona pomogłaby?
I believe you shouldn't end a sentence with a form of the particle -by.