We have had a house in Italy for more

We have had a house in Italy for more than 20 years and our terrace sits on top of a barn that belongs to a Danish woman that no longer lives in Italy.

we did offer to buy this from her but the price she wanted was crazy.

my question has two parts

can we put any pressure on her to maintain the barn as the security of our terrace is dependent on this?

If we occupy the barn e.g storage can we get squatters rights for this?