Does a parent's earlier overstay on a visitor visa affect their eligibility for a super visa later?

A previous overstay on an earlier visitor visa does not automatically disqualify a parent from getting a super visa later, but it is exactly the kind of compliance history IRCC will weigh, and it generally increases scrutiny of the new application. Officers assessing a super visa look at whether the applicant is likely to comply with the conditions of their stay, and a documented overstay in the past is relevant evidence on that question, especially if it was not clearly explained at the time or since.

That does not mean the situation is hopeless. An overstay that was brief, well-explained, or tied to circumstances outside the person's control may be viewed differently than a longer, unexplained one, and an application can still succeed with strong, honest supporting evidence, including a clear explanation of what happened previously and why it is unlikely to happen again. What matters most is not hiding or downplaying the earlier overstay, since inconsistencies discovered later can cause far bigger problems than the original issue. Given how much weight compliance history can carry, and how the explanation is presented really can affect the outcome, it is worth having an immigration lawyer review the earlier overstay and help prepare the new application in a way that directly and honestly addresses it.