Immigrant Visa Petition for My Mother

[immihelp]

My mother came in U.S. as a tourist in year 1996 & stayed up to 1998. In other words, she overstayed as a tourist visa(B-2).Now my sister is applying/petitioning her for Immigrant Visa. My concern is, on the Form DS-230 part II, item # 30 b.
....who was unlawfully present for more than one year or an aggregate of one year within the last 10 years.(my mother voluntarily departed in U.S. within the last 3 years). Which is answerable by: YES or NO. The answer for this is YES.

My question is, if my sister file this application/petition. What is the chance that my mother will be deny?/or get approve for this petition? I heard that there's a waiver/appeal for this case. Could you please give me an advise on this matter.

Thank you.

[immihelp]

You need to answer 'Yes'. The case may be denied. And you may have to file for an appeal.