|Last updated:||9th December 2019|
After the surgery if she bleeds then she can pray as this will be considered Istihadha (Bleeding due to other cause). However, during your normal period days, the blood will be considered as Haidh so avoid Salah on those days.
Also, in the case where she has stop bleeding due to the surgery she will continue to pray.
(الهداية ج.2ص.62 )
....... فما نقض أوزاد استحاضة
(النهر الفائق ج.1ص.129)
And Allah knows best
12 ٍRabi'ath Thaniya 1441/ 10 December 2019