co-maker/co-borrower/guarantor

my sister-in-law asked me to be her co-maker for a loan she took from a lending company. the lending company called me to say that she did not pay her dues and that the post dated cheques the three of us signed bounced. they are now threatening to sue us. based from what i've read the debtors should first exhaust all the assets of the principal before coming after the co-maker. my sister-in-law is no longer speaking to us which makes it hard for us to settle things. I would like to know if it is true that the lending company can file a criminal case against us for estafa and if this will show when i apply for my NBI clearance. also will this affect me when i travel abroad? Also i do not have the capacity to pay for the money that she borrowed.