Hi Welcome to HCM
I Have gone through your query . It is no doubt good Gesture to continue to Homeopathy for total cure of your mother in law . To complete the chemo and radio therapy follows , whatever your treating doctor suggests
Homeopathy can go side by side and has no side effects . Simple , nourishing food , proper exercise - walk ,deep breathing and yoga all help pave the way in early recovery ,turmeric with milk after dinner and lemon in water before meals are great antioxidant .

Oonstipation should not be allowed .

Her diet & other regimen should be taken care of . lot of water should be given to her

You Can administer her Mixture of extract of lemon, ginger ,garlic, bark of moringa ,vineyger of coconut water and honey these 6 great ingredients make great antioxidant mixture in dose of 25 ml with same amount of water for 3- 4 days and pure for next 20 days or more if required . IT gives STRENGTH to fight the diseases & HELPS faster recovery . Magnato therapy also helps in recovery of such disease .
So you can go ahead for for her total recovery
Hope this helps you in solving your query . All the best Take care

Don't hesitate to get back if have any query .

**
1. since the case is diagnosed and under treatment thus she is under constant regular supervision of doctors.
2. First thing to look out for is : metastasis i.e. spread of cancer [since if it spreads then it becomes highly unlikely to control the Infection through any system of Medicine. [thus continue with scheduled chemotherapy]
3. Management is based on disease severity, the degree of symptoms, and presence or absence of complications, determined by the diagnostic evaluation [so be under regular supervision].
4. Ayurvedic preparations can act as an adjuvant or a co-therapy along with chemotherapy or radiotherapy.

PS. Rasayan {Immunomodulation] chikitsa : i.e. The cell-protective activity of drugs helps to improve comfort and the quality of life of individuals with cancer, mainly: trifla, guduchi, punarnava
. daily use of amalaki which contains vitamin C and foof containing vitamin E helps retard the formation of cancer
. use of onion, garlic and turmeric in the diet, to some extent depress the growth and suppress the formation of cancer cells in the body.