Often when people do things like that they're in kind of a dream-like state or even a bit catatonic. It's one thing to wander from your front room to your balcony with no one noticing and swing your legs over the rail, in a moment of losing control or utter despair... it's quite another to put your shoes on, get your coat and purse, leave the house, wait for a bus, get on the bus, go to the multi-storey car park, climb to the top level, clamber out past the bars/mesh/whatever that does tend to be in place there, all while maintaining that utter despair. Housing is by no means a solution but it can be a way of minimising a risk. Leaving her where she was would have been one thing, but moving her to a higher flat with a balcony? And then not allowing her husband to install safety measures? That reads like increasing the risk, to me.