Sale of property and section 54

My mother recently sold a house property that resulted in long term capital gains. In order to reduce tax liability, she plans to avail of section 54 deduction by buying a small residential property. 

I am contemplating selling my apartment to her at the current 'market value'. Is this allowed per income tax act and rules? If yes, how do we determine the correct value of the property. We will be executing sale deed, exchanging consideration, I will pay CG tax etc.. is there anything else we need to keep in mind to avoid any future complications?

Thanks

AB