If her name is not on the business then adding it now will raise suspicions. Both your parents were refused and it is because the same accounts are used for personal and business transactions, and they don’t have well documented business dealings.Its difficult to add her name in business at this point but I will check.
if they apply for super visa even then these things would matter?
If apply for supervisa, then you show the funds. They still need to address ties to return. Assume on a supervisa that they are not going to be running their business if staying long term. They need to pass the medical and show a year of health insurance.