I bought a home with my mum (50/50) in 2010, &lived there till March17 when I bought my own home. To satisfy the ATOs one primary residence rule to avoid CapitalGainsTax, I have to transfer the title to her (StateRevenueOffice says shell have to pay stamp duty on homes current value). Or when the house is sold, ill have to pay CGT, even though it's not an investment property? Is there any way my 60 y.o. widowed mum can stay there without having to sell & move, or one of us getting hit with fees?

Hi Anda,
Your mum can stay in the home without paying stamp duty or CGT now. What would happen when the property is eventually sold is that CGT would become payable on the discounted portion of your share of the gain from March 2017 until the settlement date.
I would suggest that you get a sworn valuation done as at March 2017 to set the CGT base and you will only pay CGT if you have made a profit.
This should cost you approx $500 and give you the peace of mind you need
Please feel free to call if you need help finding a valuer
Regards
Scott
0435. 474. 498