Rishi Kapoor died at the age of 67 on April 30 at H N Reliance Hospital after a two-year-long battle with leukaemia.
Sharing a picture of herself with Rishi Kapoor, Ambani and his wife Nita, Neetu Kapoor expressed her gratitude in a post on Instagram.
"For us, as a family, the last two years have been a long journey. There were good days, there were a couple of bad days too.. needless to say it was full of high emotion. But it's a journey we would not have been able to complete without the immeasurable love and support of the Ambani family," she wrote.
The actor said the Ambanis had gone above and beyond in every manner to care for her husband in the last seven months.
"From ensuring he was medically attended to, to making frequent, personal visits to the hospital to shower him with love and attention, to even holding our hand and comforting us when we were scared.
"You have been our guardian angels on this long and trying experience - what we feel for you can not be measured. We thank you from the bottom of our hearts for your selfless, unending support and attention," Neetu Kapoor thanked them on behalf of the Kapoor family.
On Sunday, she thanked the medical staff of the hospital. KKP RDS SHDSHD