Property lien from my deceased parents for credit card debt

my Parents had been separated ( not legally) when they died for 45 years. They were legally married and the property is in both of their names. . My dad had a g/f that forged his name on credit card apps. There’s a Lien on the hse for these debts., for about 20,000.00 ( the g/f passed away about 6 months after my dad.) It’s been 6 yrs since my dad passed, 4 since my mom passed. The property is in their name. Are my sister and I responsible for the lien on the hse when we transfer the property in our name or sale it? . I recently found out my mom has a checking acct that was still open I took her death certificate in and my ID and had the acct freezed. The bank said I hv to go through the county clerk court to get any information on it. My moms name is the only name on her checking acct. There’s no will or POA. I want to sell my part in the hse. Are we responsible for the lien? The hse payments are being made and up to date. We are in Ca.