@choli
For a lot of reasons.
Mainly because she won't get as much for it now as she would if she waited about 12 months.
Plus she would need a huge amount of help/people in the house to get her belongings sorted and packed. This includes a huge amount of support from my Dsis who lives in the same city. Dsis is home schooling DCs and working from home and has had covid, still suffering serious after effects.
Mum has been sitting on this idea for twenty years but has only been serious about it since she has had to spend so many hours indoors.
She never pays attention to anything to do with national finances or the drift of the economy/ house prices. It's all gobbledygook to her.
Financial decisions that she makes are based on how she feels, not whether the decision is sensible. She has an idea that the house will be blown down in the next big storm, but it's in great nick and always has been, very solidly built in the mid 60s, solid walls, newish electrical wiring, plumbing in top shape, roof ditto.
She has difficulty imagining the difference between 400k and 600k in terms of what she can afford to move into and how much she might have left over - anything over 20k is basically Monopoly money to her. She is penny wise and pound foolish.