Tina Mundy's resignation came just one day after she became the minister of education.
Premier Wade MacLauchlan says he accepted her resignation on Thursday over the financial matter, but didn't offer any further explanation.
He says it is expected that Mundy will continue to represent the riding of Summerside-St. Eleanors in the legislature.
Mundy released a statement saying the financial issue "includes making a consumer proposal to creditors."
"The last few years have been a difficult time for me and my family as a single mother," she wrote.
"I have struggled with ongoing financial matters. I have taken the appropriate steps to work through these matters and fully address them."
She says the process started before the election campaign and she now realizes she should have disclosed it to government.
Mundy was appointed minister of education on Wednesday after being elected to the legislature for the first time in the Liberal party's victory earlier this month.
Hal Perry will replace her as education minister.
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