If the ancestral property was already divided then it becomes the self-acquired property and the father has the right to name the property to any person he wishes to. But if the property has not been divided then all the coparceners or legal heirs have right over it. It has been mentioned by you that the transfer took place 42 years back which means it was before the 2005 amendment to Hindu Succession Act, 1956. Before this amendment, only male heirs were treated as coparceners and had the right over the property whereas daughters had no rights.
After the amendment, daughters, and sons are treated apar, and daughters were given equal rights of coparcenary as the son. But the Supreme Court and various High Courts have decided that the amendment did not have retrospective effect, which means it will not apply to partitions that took place before 2005. Therefore, in your query, your mother cannot claim rights over the property as the partition took place before 2005 and she will not be treated as a coparcener. She cannot fight for the claim over property as she has no right over it.