Need some advice for estafa case

Nagkaron ng problem sister ko from her previous company, manpower agency company and she was handling the liquidations of employees, processing the salary of the employees, cheques payable, petty cash, etc... involves money. since sya lang mag isa handling the huge responsibilities hindi na kinaya ng sister ko at nagsabi sya sa boss nya na my kulang syang pera na di pa naliliquidate and bank transactions na nawawala dhil yung messager paiba iba at di nagbibigay g resebo. The problem was wla silang logbook even sa petty cash at yung mga advances ng employee di nakalogbook yun na ang naabutan nya simula nung nahire sya. She talked the management about it and because she was tired tracing those financial loses she ask if she can resign but since the documents are not documented the management asked to settle the 180k undocumented loses. Para matapos na lang daw at makapagresign sya pumayag sya at gumawa ng letter na bayaran with in 6months yung 180k without thinking kung kaya nya. After 3 months of resignation nagclose na yung company. And because 30k monthly ay napakabigat hindi nya nasettle yung obligation nya. Late na nya narealized na mabigat pla. To make the story short. Year after her resignation, early this month nakatanggap ng subpoena yung sister ko at need daw nya settle amounting 400k at need nya sagutin yun o Nov.20,2017. We need help. Ano po ba ang dapat namin gawin? At ang nagfile daw ng case ay yung manager nya not the president of the company. Any advice po. Thanks.