Can owner of agriculture land sell his/her property even if

If a lady has given Power of Attorney which is registered with Sub-Registrar - Hisar (Haryana) to his son in the year 2000 which does not contain property detail but it is written in the POA “Movable and immovable land anywhere in India”. But, she, herself, has executed a sale deed of her ancestral agriculture (situated in Haryana only) land in the year 2014. Sold property was never sold in past by either of the parties, i.e. owner or POA holder. Question is (a) Can a property owner sell his/her property by his/her own even she has given Power of Attorney to anyone else; (b) Is the owner liable to give advance notice to the POA holder before and after execution of sale deed; (c) Can a POA holder sue owner in respect of selling of agriculture land. Please reply at colrsp @ yahoo.in