My husband went into an assessment unit before going into a nursing home and he spent the first four weeks wearing his coat and walking around with clothes tucked under each arm. We visited him every afternoon and he was always peering through the window in the door when we arrived. Then one day there was no face at the window. We went to his room and that was empty . We asked where he was and was told to go and look in the small sitting room. He was there minus his coat and baggage and talking to a carer with tea, cake and biscuits by his side. It happened overnight.
They explained it as he had now become settled with his surroundings, he was feeling comfortable just as he was at home. My husband had not accepted our home or me as being his wife for over two years but knew it was familiar, he was kind of contented to be there but always wanting to go home. Now he was feeling comfortable with his new surroundings. He spent a further five weeks there before moving to the nursing home. He settled immediately in the nursing home, probably because his room was very similar to the one in the assessment unit and the carers wore the same colour uniform.
Hopefully your Mum will settle soon and stop packing up to leave.