Tax on sale of appartment proceeds

On my mothers appartment (deed)  on sale of property the 1099S reflects gross proceds, however the final

net proceeds(smaller amount) was divided between me and my mother.  Note i did not reside in the appartment I made her monthly mortage payments.  How do i claim on tax paperwork via TurboTax?

we both have received 1099S from title company stating the amounts.