Jade Crassula- please help! Leaves suddenly turning yellow and dropping

Hi All, I would be so grateful for your thoughts. I recently purchased my mother a beautiful flowering jade Crassula, about 70cm tall. It was previously kept sheltered, but lived in a drafty lean-to so pretty low temperatures, by an elderly Chinese gentleman who was clearly a wizard with bonsai and had many, many gleaming Crassula grown over many decades. It was quite a privilege seeing inside his greenhouse.
The Crassula plant has for the last week been living in my mother’s room at her nursing home (it was bought to cheer her up), and I visited today and the Crassula’s leaves are now turning yellow and dropping off. My mother’s room has no central heating on, but it is very warm.
Could the Crassula be in shock at being moved to a new temperature? What should I do, remove this and take it to a colder location, or will it likely adjust? (I can always buy my mother a plant which will do better in a warm room)
I don’t want this Crassula to lose too many leaves or shock it too much in trying to adapt it to a warm room, this plant has been loved and cared for for decades by this Chinese family and I promised I would do the same.
Would be very grateful for advice!
Thank you in advance, Bluebell

 

It could be the temperature, but a couple of things to check; is it getting plenty of daylight and is it being overwatered.
If it is not being overwatered and is getting plenty of daylight then you have to decide to leave it or give it another shock by moving it somewhere colder and I would go cooler rather than cold.
Mine lives in an unheated greenhouse year round and is currently flowering.
The good news is they are pretty hard to kill and propagate easily from a pinched off shoot or even a leaf.