My situation very closely mimicks your aunts.
I treated successfully breast cancer in 2016 with surgery, chemo and radiation
Then 2 yrs. later treated my HepC successfully with a DAA regime and everything went well .
Both my Hepatologist and Oncologist advised me at the time there would be no safety issues .
Good luck to her.
Diagnosed: 2001 GT1a , HCV since mid-70’s.
Biopsy 2010 F1
Fibroscan and Fibrosure 2018 F2
Treated in trial 2010 with Dac/Peg/ Riba and Relapsed.
Resistance test 2017. Have Ns5a Rav Q30r/H58d enhanced from doing Dac.
Start Tx. Jan 18th/18 w/ Vosevi /Riba 12wks. plus 6 wks.Viekira Pak +Sof/Riba(From Dr Freeman @GP2U)
VL start: 1.6mill.ALT 125 AST 88
Wk. 4 Det @LLOQ <15.
VL Wk.8 UND Alt &Ast 22
Wk. 12 UND
EOT:UND
EOT+12 >>>UND (SVR12)! ALT11 AST13
Nov6/18 SVR 24!