Irregular bleeding after a miscarriage

Alhamdulillah, we have a 2 year old child. My wife had a Miscarriage almost 10 months back, now she is facing menses day problem so need your kind advise for Ramadan fasting.

Two months back, she found little spot of dirty water (or may be blood) for first 5-6 days and then she faced full menses for another 5-6 days and then again little spot of dirty water for 5-6 days so the total duration was 15-17 days. She wasn’t performing any sort of religious obligation in that duration.

Now the same case is going to start, she is finding little spot of dirty water for last 2 days, please let us know if she observe fasting if not then when she can get started.