Damage to neighbour's party wall before we purchased property

[suubedoo]

We purchased a property in Feb 2022. We noticed that one of the party walls was damaged, but when we spoke to the neighbours, they said that the owner of the freehold was aware and 'had done nothing about it' for a number of years.

 

Today we received a letter from the owner of the freehold, stating that the damage to the party wall was caused by a fallen tree from our garden. The wall belongs to the neighbours, but they have suggested the responsibility for fixing the wall lies with us.

 

Can anyone help with advice on whether there is a timeframe she should have made this complaint within? We cannot see what tree has supposedly damaged the wall (she insists the tree should be removed) as the only tree there is a low and well-established apple tree that doesn't appear to have any cut or removed branches that could have caused the damage. Would we also still be liable given we didn't own the property at the time, and there was no mention of this on the SPIF?