But if she didn't know that the floor had asbestos in it she doesn't have to disclose it. She won't have to say that she covered over a floor that may have asbestos in it. Vinyl is being covered over all over the place and I have yet to see it mentioned in a disclosure. Most disclosures are a 'yes' or 'don't know' answer. No maybe's.
On the other hand, if you have it tested and find out it has asbestos in it then you need to disclose it.
Personally, if economically feasible, I would have it removed. But then Jay J would want me to discluse that it had been in the house at one time.