Gyanu, in her 40s, has breast cancer and "is said to be in a very critical condition", Chunamani Khadka, a personal aide to Prachanda, told IANS.
"She developed cancer some seven years back and was treated in Mumbai. Last year the problem resurfaced and she was flown to the US.
"After coming back from the US, the cancer resurfaced in the liver. For one and a half months, she is being treated in Noida," he said.
The entire family will travel with Prachanda, said Khadka. Prachanda's son reached New Delhi on Wednesday.
The aide said Prachanda will have no meeting of political nature during his stay in India.