I am sorry to hear about your mother-in-law. Mrs Erocse and I will be thinking of you and wishing all the best.
My Grand parents passed away a couple years ago. We were all present. My grand father was sick but still, even though hospice told us it would be "any day now" He held on for a week and a half. . My grandmother just didn't want to live after that , she stopped eating and simply gave up . The same thing happened when they said it "would be any day now". She managed to struggle for about a week before she passed.
It can be an emotional roller coaster. But in the end we could take comfort in that they are not in any more pain.
Hugs and love, erocse