My mother inherited about $75,000 in 2005 form her mother in the UK. I checked with my mother and reviewed her tax return and she did not file form 3520. So, we asked her taxpreparer why she did not file form 3520 and the taxpreparer said she was not aware of the form. The taxpreparer said she would amend my mother's tax return and add that form.

My question is: if my mother amends her return to add form 3520 will that cause her to get audited? What is the penalty for not filing this form? What should i have my mother do?

Thank you.