No...she doesnt get the land by paying taxes. What you are probably thinking of is where somebody buys property at a tax sale....then after 3 or 5 years, the tax purchaser can quiet title if the past due taxes arent redeemed. Only way she could own the land would be if you sold it to her; she bought it at a judicial sale or partition sale, or if she "adversely possessed" it for 10 years (with a title of some sort in her name) or for 30 years without such title. I suspect she would have the right to collect the taxes she paid from the owners.
Of course, you need to make sure of the transfer from her to your father....and you need to make sure there is no usufructuary interest per the succession. But as to your question as to whether paying taxes entitles you to the property....thats a bunch of hooey.
This is not to be construed as legal advice, and i don't represent you....
she can sell the land