To step up to the plate means to take action in response to an opportunity or crisis, but in this context she is not taking any action
Context: "She might not take any action or responsibility once she knew what a crappy job her son was doing of raising her granddaughter." Claim: "She might step up to the plate once she knew what a crappy job her son was doing of raising her granddaughter."
Considering the context, is the claim true, false, or unknown?